DE102020126900B4 - Method for detecting an oil condition of an operating oil, control and regulating device and internal combustion engine - Google Patents

Abstract

Method for detecting an oil condition of an operating oil in an engine (101) of an internal combustion engine (100), in particular for a diesel, gasoline or gas engine, wherein the internal combustion engine has the engine (101) and:
- an oil supply system (104) with an oil filter (1F) for the operating oil ( _1B ) and an oil differential pressure measuring device (1M) designed to detect an oil pressure difference (Δpi) or similar oil pressure relation of the operating oil via the oil filter (1F) in the oil supply system (104),
- a control and/or regulating device (10) with a characteristic map module (10.1) and an analysis module (10.2) for the oil pressure difference (Δp _i ), wherein in the method:
- the oil pressure difference (Δp _i ) is processed in relation to an operating time (hB) of the internal combustion engine in the analysis module (10.2),
- a number of relational values (R1, R2, R3, Ri) taking into account the oil pressure difference (Δp _i ) are specified in relation to a number of operating time points (hi),
- the number of relational size values (R1, R2, R3, Ri) is assigned to a trend development (E) over the operating time points (hi), characterized in that
- the oil pressure difference or similar oil pressure relation in relation to a number of operating parameters (B) of the engine and/or oil parameters of the operating oil is recorded in a characteristic map (K), and
- the oil pressure difference (Δp _i ) or similar oil pressure relation determined via the oil filter (1F) is converted into a relational quantity value (R1, R2, R3, Ri) independent of the operating parameters (B) and is specified in relation to the number of operating time points (hi), and
- for a further operating time point (hi) added to the number of operating time points (hi), a further relational quantity value (R _i+1 ) is analyzed in relation to a relevant trend deviation (ΔT) from the trend development (E) caused by at least one further relational quantity value (R _i+1 ), namely by means of a changed trend development.

Description

The invention relates to a method for detecting an oil condition of an operating oil in an engine of an internal combustion engine according to the preamble of claim 1. The invention also relates to a control and regulating device and a corresponding internal combustion engine with the control and regulating device.

The German Patent and Trademark Office has published the publications DE 10 2016 100 211 A1 , DE 10 2016 215 909 A1 , DE 10 2013 226 744 A1 , DE 103 23 396 A1 , DE 35 05 246 A1 , DE 10 2007 038 992 A1 , US 2018/0340924 A1 , US 2019/0264590 A1 determined as the state of the art.

DE 10 2016 100 211 A1 describes a method for a lubricant filter indicating a condition of the filter based on a difference between a measured pressure differential and an expected pressure differential during selected conditions in which all lubricant pumped by a pump upstream of the filter flows into the filter. In some implementations, a suitable data structure (e.g., a lookup table) may store a plurality of expected pressure differentials across the filter, enabling retrieval of the expected pressure differentials by accessing the data structure with one or more suitable indices. Upon expiration of a timer, a vehicle operator may be notified of the expiration of remaining service life (determined by a prognosis or subsequent diagnosis/prognosis) and/or engine operation may be modified to compensate for filter degradation.

A method for detecting an oil condition of an operating oil for an engine of an internal combustion engine, in particular for a diesel, gasoline or gas engine, is generally known as such.

DE 10 2007 038 992 A1 describes a method for monitoring the quality of an engine oil in a motor vehicle, in which at least one parameter of an engine oil is continuously or randomly recorded and stored in the motor vehicle, wherein a temporal and/or distance-related course of at least one partial interval of at least one of the stored parameters and/or a ratio of at least two of the parameters or their courses is used to determine whether foreign matter has entered the engine oil. In detail, the parameters are a viscosity, a dielectric number and an oil level. A coolant level is shown as a further parameter. To identify foreign matter, alternatively or additionally, for example, at least one of the parameters oil temperature, pressure difference of an oil filter or electrical conductivity can be determined and stored. Further parameters of other units can be, for example, a torque of the combustion engine, a speed or a coolant temperature.

US 2018/0340924 A1 generally refers to the remaining service life of a lubricating oil and US 2019/0264590 A1 refers only to the condition development of an operating oil in relation to fuel in the oil and in relation to a reference value.

However, a change in the condition of the operating oil based on significant effects cannot necessarily be determined by oil level sensors alone. One reason is that, for example, an increase in volume due to diesel fuel entering the oil circuit competes with oil consumption. Level sensors also involve additional costs. However, it has been recognized that oil quality is of particular importance for the service life of an engine and should fundamentally be based on the principle of oil differential pressure measurement.

For this purpose, an internal combustion engine has: an oil supply system comprising an oil filter for the operating oil and an oil differential pressure measuring device, in particular with a first pressure sensor arranged upstream of the oil filter in the flow direction and a second pressure sensor arranged downstream of the oil filter in the flow direction, designed to detect an oil pressure difference or similar oil pressure relation of the operating oil via the oil filter in the oil supply system.

An oil differential pressure measuring device has in particular a first pressure sensor arranged upstream of the oil filter in the direction of flow and a second pressure sensor arranged downstream of the oil filter in the direction of flow. This allows a first oil pressure upstream of the oil filter to be detected and/or indicated using the first pressure sensor and a second oil pressure downstream of the oil filter to be detected and/or indicated using the second pressure sensor in order to calculate the oil pressure difference. An oil differential pressure measuring device can also be implemented, for example, as part of a maximum oil pressure control and/or with an override valve. In particular, this could replace a pressure sensor if one of the two pressure values could be assumed to be constant.

An internal combustion engine mentioned at the outset further comprises a control and/or regulating device known per se, with an analysis module for the oil differential pressure or the like Oil pressure relation, wherein the oil differential pressure or similar oil pressure relation across the oil filter in relation to an operating time of the internal combustion engine is processed in the analysis module.

Such a method for detecting an oil condition of an operating oil for an engine of an internal combustion engine is basically known from DE 35 19 026 A1 This method provides an oil pressure sensor before and after the oil filter for determining the time when an internal combustion engine needs to be changed, and an oil temperature measuring device, an engine speed meter and a logic switching element are also provided. The logic switching element emits an output signal when a threshold switch for a specific pressure drop at the oil filter, i.e. measured by means of a specific difference in the oil pressure sensor, provides an output signal and a specific oil temperature and a specific engine speed are present at the same time. In this way, it is possible to detect the time when an oil filter and oil change is necessary. This teaching assumes that the pressure drop at the oil filter increases with time of use and that the pressure drop can fluctuate greatly under normal operating conditions, so that the pressure drop can only lie within a specific speed and temperature range. The reliability of this teaching is problematic because the pressure drop can fluctuate greatly under normal operating conditions. In addition, the procedure is comparatively complex because a specific operating point must be determined to determine whether the internal combustion engine is within the limited operating range.

It is desirable to be able to record the oil condition of an operating oil independently of an operating point specification of this kind, while at the same time avoiding excessive fluctuations in oil condition statements.

DE 10 2007 048 182 B3 proposes a method for detecting an oil condition with a differential pressure measurement in the oil, taking into account the oil temperature, the engine speed and the like. This doctrine assumes that the pressure drop in the oil depends on the viscosity of the oil at a given oil temperature and speed. A comparison of the determined pressure difference with a specified reference value for the pressure difference is therefore only carried out at a comparable oil temperature and speed. Since the oil filter naturally also changes its flow resistance by filtering out wear particles and/or combustion residues and thus according to the doctrine of DE 10 2007 048 182 B3 could give a false picture of the cause of the increase in flow resistance, the pressure difference determination is carried out in DE 10 2007 048 182 B3 specifically in an oil gallery or in an oil channel without an oil filter.

Nevertheless, it is desirable to take into account synergies of oil filter and oil condition determination when determining oil condition based on oil differential pressure measurement.

This is where the invention comes in, the object of which is to provide a method and a device for detecting an oil condition of an operating oil in an engine of an internal combustion engine, as well as a control and regulating device and an internal combustion engine, by means of which at least one of the above-mentioned aspects can be taken into account, in particular improved. Preferably, the method and the device should avoid in an improved manner the problems known in the prior art when detecting an oil condition.

The main object of the present invention is to provide a method and a device for detecting an oil condition, which uses a detection of an oil pressure difference or similar oil pressure relationship of the operating oil via the oil filter in the oil supply system. In particular, this should be done in a manner that is improved compared to the prior art. In particular, it should be possible to detect and provide information about the oil condition that is largely independent of the operating condition of an engine.

This object is achieved with regard to the method by a method according to claim 1.

• - ein Ölleitsystem mit einem Ölfilter für das Betriebsöl und eine Öl-Differenzdruck-Messeinrichtung ausgebildet zum Erfassen einer Öldruck-Differenz oder dergleichen Öldruck-Relation des Betriebsöls im Ölleitsystem über den Ölfilter,- eine Steuer- und/oder Regeleinrichtung, insbesondere zum Steuern und Regeln der Brennkraftmaschine, mit einem Analysemodul für den Öl-Differenzdruck oder dergleichen Öldruck-Relation, wobei
• - der Öl-Differenzdruck oder dergleichen Öldruck-Relation über den Ölfilter in Bezug auf eine Betriebsdauer der Brennkraftmaschine in dem Analysemodul verarbeitet wird.

The invention is based on the assumption that the internal combustion engine has the following features for detecting an oil condition of an operating oil in an engine of an internal combustion engine, in particular for a diesel, gasoline or gas engine:

• - an oil supply system with an oil filter for the operating oil and an oil differential pressure measuring device designed to detect an oil pressure difference or similar oil pressure relation of the operating oil in the oil supply system via the oil filter, - a control and/or regulating device, in particular for controlling and regulating the internal combustion engine, with an analysis module for the oil differential pressure or similar oil pressure relation, wherein
• - the oil differential pressure or similar oil pressure relation across the oil filter in relation to an operating time of the internal combustion engine is processed in the analysis module.

According to the invention, it is provided that initially a number of oil differential pressure or similar oil pressure relation taking into account Relational quantity values are specified in relation to a number of operating time points. A relational quantity value for an oil differential pressure is generally understood to be a value that expresses the oil differential pressure as a relation of the oil pressure before and after the filter; ie this can be a difference, a quotient or another relation that relates the oil pressure before and after the filter; thus assigns a quantitative value to the oil pressure relation. A corresponding relational quantity value can preferably be specified in relation to a number of operating time points.

The invention has also recognized that the number of relational variable values can be assigned to a trend development over the operating time points. In this regard, a trend development is basically understood to mean any recognizable, in particular analytically describable, indication of a development of the relational variable values over the operating time points, in particular a mathematical indication of a development of the relational variable values over the operating time points that can be interpolated computationally or traced in some other way.

In this regard, it can be mentioned as an example, in a non-limiting manner, that a trend development over the operating time points can include the specification of an interpolating compensation curve for the relational variable values for an oil differential pressure over the operating time points; for example as a regression line based on the least squares method. In particular, a trend can include the specification of a slope of the interpolating compensation curve, preferably include the specification of a regression line, or a trend development can include the specification of an interpolating -- and if necessary extrapolating -- compensation curve, preferably a regression line.

In the context of a further development already mentioned here, it has been shown that a trend development up to a certain operating point can be described as a normal trend development. In this case, a normal trend development of an oil differential pressure is generally understood to mean any expected trend development of an oil differential pressure across an oil filter of a specific engine that occurs without any recognizable or to be taken into account change in the oil condition in the narrower sense.

The invention is further based on the consideration that a significant effect of a change in oil condition results in a change in viscosity; according to the knowledge of the invention, this results in a reduction in viscosity. A reduction in viscosity can, as will be explained, result from oil dilution as well as oil aging. Both effects are superimposed on any trend development, in particular with increasing operating time they are increasingly superimposed on a normal trend development and yet, according to the knowledge of the invention, they are therefore recognizable in comparison to this. Both effects are also recognizable in the context of an oil pressure difference or similar oil pressure relationship of the operating oil via the oil filter in the oil supply system compared to a filter change; a filter change does indeed result in a reduction in the oil pressure difference, but a comparatively sudden reduction in the oil pressure difference compared to all other changes.

The invention is therefore based on the groundbreaking consideration that the aforementioned type of significant effects of an oil condition change -- in particular based on oil dilution and oil aging -- can nevertheless be measured by means of a differential pressure across an oil filter, in particular when they are superimposed on a normal trend development of an oil differential pressure. In both cases of oil dilution and oil aging, there is a reduction in viscosity, which will therefore basically be recognizable as a reduction in an oil pressure difference. However, this is recognized using a more reliable procedure according to the knowledge of the invention, which is different and improved compared to concepts from the prior art. The appropriate assignment of a number of relational size values to a trend development over the operating time points has proven to be superior to the prior art.

The invention initially recognized that in the context of oil aging, the viscosity should essentially decrease over time, since the long-chain hydrocarbon chains are broken down by mechanical shear forces. In the context of oil dilution, the viscosity should also decrease, but due to other processes on a different time scale. In the case of oil dilution, there is therefore also a differential pressure loss as a contribution to the trend, which shows a downward development compared to a previous trend development and in particular compared to a normal trend development up to a certain operating point.

The invention has accordingly furthermore recognized that for a further operating time point added to the number of operating time points, a further relational quantity value in relation to a by means of at least The relevant trend deviation caused by another relational quantity value is generally analyzed by means of a changed trend development.

Specifically, the invention has recognized that, regardless of the type of engine, such as a diesel, gasoline or gas engine, a relevant trend deviation from the trend development can be analyzed by means of an already changed trend development, in particular in comparison to a normal trend development at a certain operating time.

For example, a relevant trend deviation, in particular a trend deviation from a normal trend development, as a result of a changed trend development is preferably recognizable in a significant change in the aforementioned compensation curve by means of the at least one further relational quantity value. Merely as a non-limiting example, it should be mentioned that a trend deviation can, for example, comprise an indication of a change in the slope of the compensation curve, preferably the regression line, if a new relational quantity value is added to the existing set of relational quantity values over a new operating time. Such a significant change in the aforementioned compensation curve by means of the at least one further relational quantity value is not limited to a change in slope; in principle, it can also be recognizable in a change in curvature. However, it is above all not exclusively dependent on a decrease in amplitude. Rather, the invention has recognized that, in general, the recognition by means of a changed trend development in comparison to a previous trend development - -- in comparison to an engine-specific history, so to speak -- makes significant oil changes such as oil aging or oil deterioration recognizable.

Furthermore, the invention relates to a control and regulating device according to claim 23 and an internal combustion engine according to claim 24.

The control and/or regulating device for controlling and/or regulating an internal combustion engine is designed to detect an oil condition of an operating oil for an engine of the internal combustion engine, in particular for a diesel, gasoline or gas engine, to carry out a method according to the concept of the invention and for this purpose has an analysis module for an oil differential pressure.

The analysis module is particularly designed to process the first and second oil pressures by means of a relational variable taking these into account in relation to an operating time of the internal combustion engine and to carry out the steps of the method according to the invention for this purpose.

The internal combustion engine has an oil supply system comprising an oil filter for the operating oil and an oil differential pressure measuring device, in particular with a first pressure sensor arranged upstream of the oil filter in the flow direction and a second pressure sensor arranged downstream of the oil filter in the flow direction, which are designed to detect and indicate a first oil pressure upstream of the oil filter by means of the first pressure sensor and a second oil pressure downstream of the oil filter by means of the second pressure sensor, wherein the internal combustion engine further comprises a control and/or regulating device according to the concept of the invention.

In summary, the invention fundamentally recognized that an oil differential pressure measurement for the aforementioned significant effects, especially via a filter, has particular advantages when significant effects of a change in oil condition -- in particular from oil dilution and/or oil aging -- are assessed as a result of findings on the change in viscosity. The invention has thus recognized for the first time that relevant oil condition changes of this kind are due to a reduction in viscosity and can nevertheless be generally recognized as changes in the trend with an appropriate trend analysis, i.e. by means of a changed trend development compared to a previous trend development.

Advantageous further developments of the invention can be found in the subclaims and specify in detail advantageous possibilities for realizing the concept explained above within the scope of the task and with regard to further advantages.

According to the knowledge of a particularly preferred development of the invention, relevant oil condition changes of this type are generally recognizable as a change to the trend and specifically as part of a decreasing trend deviation; i.e. recognizable as a decrease in the trend development for an oil pressure difference or similar oil pressure relation of the operating oil via the oil filter in the oil supply system. In particular for a diesel or gasoline engine, it has been shown in the development that a decreasing oil pressure difference or similar oil pressure relation can be clearly recognized in a trend development with the procedure proposed by the invention. A decrease in the trend development for an oil pressure difference or similar oil pressure relation here means above all a decrease in amplitude.

The original purpose of oil filter differential pressure monitoring can also be used for a filter change. In particular, in addition to oil condition monitoring, a condition determination relating to oil dilution and/or oil aging can be detected. However, the method for detecting an oil condition is advantageously not only limited to determining an oil pressure difference or similar oil pressure relationship for determining oil dilution or oil aging; an intelligent evaluation of this oil pressure difference or similar oil pressure relationship can advantageously be carried out.

Advantageously, the oil pressure difference or similar oil pressure relation determined via a filter, in particular a measured first and second oil pressure value, is converted into a relational quantity value that is independent of the operating parameter. A relational quantity value that is independent of the operating parameter can preferably be specified in relation to a number of operating time points. The operating parameters include in particular oil temperature and engine speed. A number of such operating parameter-independent relational quantity values can be formulated independently of the operating parameters oil temperature and engine speed, and operating parameters can be specified independently in relation to a number of operating time points.

In particular, such a normal trend development can be specified as a basic standard - possibly depending on the engine, as it turns out. A comparison can be made with such a normal trend development for a further operating time point added to the number of operating time points; namely, in order to determine a relevant trend deviation from the trend development existing up to that point, caused by the at least one further relational quantity value, i.e. in particular to determine the trend development referred to as the normal trend development.

In the context of a previously mentioned further development, it can be advantageous to assume a certain normal trend development under certain conditions; e.g. if one assumes the behavior of an engine that does not show any change in the oil condition in the narrower sense.

In a first variant of a further development -- for example primarily in a diesel or gasoline engine -- an increasing trend in the behavior of an oil differential pressure or similar oil pressure relationship can be assumed, and in a second variant of a further development -- for example primarily in a gas engine -- a constant or decreasing trend in an oil differential pressure or similar oil pressure relationship can be assumed. Both variants are explained below.

A preferred further development provides, for example, that a standard characteristic map of standard differential pressures -- comprehensive relational variables that take oil pressure into account on the basis of "normal differential pressures" -- (preferably of a healthy engine with new oil and new filter or according to another gold standard) is available as a function of oil temperature and speed. Such a standard characteristic map of standard differential pressures can, for example, be taught in on a test bench for a specific engine type and be available in a control system of every engine of that engine type.

A relational quantity value that is independent of the operating parameter can also be obtained when the engine is operating in the field if this relational quantity value -- or, advantageously, the oil pressure values used for this purpose themselves -- are converted via oil parameters and/or engine parameters to a value that is independent of the operating point, in particular independent of an oil parameter and/or engine parameter. In one way or another, a relational quantity value can be specified that, as a standardized oil differential pressure, eliminates those operating parameters for which the oil differential pressure was measured - the independent relational quantity value is then considered to be independent of the operating parameter.

For example, in order to eliminate the influence of an operating point, a relational quantity value at a certain oil temperature and speed can be divided by the corresponding standard differential pressure of the standard characteristic map and thus regarded as a relational quantity value independent of the operating parameter. In order to eliminate the influence of an operating point, for example, in one variant the oil pressure values used for the relational quantity value can themselves be divided at a certain oil temperature and speed by the corresponding standard oil pressure value of a standard characteristic map; then an operating parameter-independent relational quantity value can be formed from these standardized or operating parameter-independent oil pressure values by difference or quotient formation or otherwise. One or the other approach can be selected as appropriate depending on the circumstances. In particular, it is advantageous to use a standard characteristic map; but this is not mandatory. For example, a mining engine is only operated at comparatively few operating points, e.g. at one to three operating points; These can also be recorded without a standard map in such a way that the oil pressures or oil differential pressures can be analyzed for A relational value independent of the operating parameter can be formulated based on the trend development. A fracking engine, on the other hand, has a comparatively broad spectrum of operating points, so that it makes sense to record a standard characteristic map of standard pressures or standard differential pressures for a standard engine and/or a standard operating oil.

In any case, a complicated selection of comparable values for a specific oil temperature and a specific speed, which is required in the state of the art, can be dispensed with if one works directly with a relational quantity value that is independent of the operating parameter. A trend development is then preferably understood to mean any type of indication of the relational quantity that is independent of the operating parameter over periods of time during the operating period. This can include a regression line based on the method of least squares, which is carried out, for example, in the form of a curve or straight line, interpolating or extrapolating, taking into account the specific relational quantity values.

In particular, in this development with a relational quantity value independent of the operating parameter, it has been recognized that for each additional operating time added to the number, a further relational quantity value independent of the operating parameter can be analyzed with regard to a trend deviation of the further relational quantity value from the trend development. This type of analysis has proven to be particularly advantageous because it is comparatively efficient and independent of fluctuations - overall, the method according to the concept of the invention thus has significantly improved resistance to fluctuations in the measuring range and the accuracy of the method according to the invention is therefore superior to other known methods.

As already mentioned above, in the context of further training, it is advantageous to assume a certain normal trend development under certain conditions; e.g. if one assumes the behavior of an engine that does not show any change in the oil condition in the narrow sense. In a first variant of further training - for example primarily in a diesel or gasoline engine - an increasing trend in the behavior of an oil differential pressure or similar oil pressure relationship can be assumed and in a second variant of further training - for example primarily in a gas engine - a constant or decreasing trend in an oil differential pressure or similar oil pressure relationship can be assumed. Both variants are explained below.

According to a first development within the framework of an exemplary filter model, a trend that is basically increasing according to the first variant of a normal trend development weakens as a result of oil dilution, at least with an increasing relational variable that takes the first and second oil pressure into account. A trend deviation between the further relational variable value and the trend development can then be evaluated in different ways; a trend deviation can be advantageously analyzed as part of an evaluation of the short-term or long-term trend development.

A further development, for example in the aforementioned first preferred variant, is based on the consideration that - as in the prior art mentioned at the beginning with an oil differential pressure in relation to an operating time - a relational value assigned to the oil differential pressure generally tends to increase (first variant of a normal trend development), in particular it increases monotonically over the operating time; this normal trend development has generally been confirmed as a first preferred variant in a diesel or gasoline engine, since the soot development inherent in operation there is generally responsible for the oil filter becoming clogged with soot particles over the operating time.

It is therefore advantageous that in the aforementioned first preferred variant of a further development there is an assumption that a trend development in the form of a normal trend development over the operating period is generally increasing overall, in particular is monotonically increasing. This means that the further development assumes that in the normal case of normal operation of the engine, the approach of a trend development of an oil differential pressure in relation to an operating period is increasing in the form of a normal trend development, in particular is monotonically increasing over the operating period.

This statement takes into account the fact that in the first variant of a preferred further development, the filter slowly becomes clogged over time; the relevant trend deviation from the trend development is therefore particularly superimposed on a normal trend development, which however only reflects the effect of the filter. The relevant trend deviation is therefore additionally superimposed on the effect of the filter. With increasing load, the differential pressure logically increases - this is a slow trend. With increasing load, the differential pressure increases as part of a slow trend, ie a monotonically increasing normal Trend development on a long time scale (such as several 1000 hours of operation).

In the context of a particularly preferred further training, the relevant trend deviation generally results from a changed trend development as a decrease in relation to the previous trend development, insofar as it is a decreasing trend deviation from the previous or current trend development, in particular a normal trend development.

With regard to the previous trend development, the trend deviation can be identified as a decrease in the fact that the further relational variable value is below the current trend development or previous trend curve, and/or the slope of a relevant trend development, in particular another trend curve, decreases with the further relational variable value. The relevant trend deviation particularly preferably results as a trend development that decreases below an increasing normal trend development. Even in the case of the first variant of an increasing normal trend development and the case of a second variant of a constant or decreasing normal trend development, the trend deviation can be identified as a decrease in the fact that the further relational variable value is below the current trend development or previous trend curve; i.e. preferably below the increasing normal trend development or below the constant or decreasing normal trend development.

According to a preferred development, the further relational quantity value is analyzed as the relevant trend deviation in relation to a decreasing trend deviation from the trend development caused by at least one further relational quantity value. The trend deviation then arises due to a decrease in the existing trend, in particular in comparison to the aforementioned normal trend development up to a certain operating point in time.

According to the aforementioned first variant of an increasing normal trend development of the oil differential pressure, e.g. in a diesel or gasoline engine, this corresponds to a decrease in the trend development - the changed trend development increases less strongly or even decreases compared to the increasing normal trend development; in the case of a compensation curve, this can be the determination of a positive gradient value that becomes smaller compared to that of the increasing normal trend development or reverses to a negative gradient value in the changed trend development compared to the positive gradient value of the increasing normal trend development. However, it was nevertheless recognized that the approach of a normal trend development of an oil differential pressure in relation to an operating time can only be determined as fundamentally increasing in a first variant, albeit a particularly preferred one. In particular, a monotonous increase in the differential pressure is not present in a gas engine, for example, since it produces little or no soot. For example, in a second preferred variant, a further development is based on the consideration that a relational value assigned to the oil differential pressure tends to remain constant or only slightly increasing or possibly even decreasing (second variant of a normal trend development), in particular decreasing over the operating period. In the case of a compensation curve, this can be the determination of a positive or negative gradient value around zero or clearly in the negative range.

A relevant trend deviation from the trend development can therefore not only be analyzed as a trend deviation by means of a tendency towards a decrease in the existing trend development (according to the aforementioned first variant, for example in the case of a diesel or gasoline engine). It can also be recognized from an intensified trend development (according to the aforementioned second variant) in the sense that a previous or current constant or already decreasing trend development (for example in the case of a gas engine) is further intensified with a further decrease or decreasing trend deviation. This means that the trend deviation then arises due to an intensification of the previous trend development; in this sense in the sense of an increase in the current trend development, in particular in comparison to the aforementioned normal trend development up to a certain operating point, which (for example in the case of a gas engine) can already represent a decreasing trend development according to the aforementioned second variant. In the case of a compensation curve, this can be the determination of an increasing negative gradient value around zero or even more clearly in the negative range than before; overall with an increasing negative gradient value.

In this case too, a sudden change can be used to identify a filter change; however, since gas engines produce hardly any soot, the filter is much less likely to become clogged and an increasing jump in the trend development can also be recognized as a filter change.

A particularly preferred further development provides, independently of this, additionally or alternatively, that the detectability and differentiation of the two aforementioned relevant effects of oil aging and oil dilution on the basis of a speed of the trend deviation to a current or previous trend development is made possible. In a particularly preferred development, the concept of the invention also offers the basis for distinguishing between a sudden, a fast and a slow trend - in particular independently of a previous or current trend development or normal trend development and/or independently of an amplitude of a changed trend development.

1. 1. Eine Öl-Alterung, welche als eine abnehmende Trendabweichung auf längerer Zeitskala (zeitlich global) erkennbar ist,
2. 2. Eine Öl-Verdünnung, welche ebenfalls als eine abnehmende Trendabweichung (zeitlich global) erkennbar ist; mit Vorteil versehen aber auf deutlich kürzerer Zeitskala im Vergleich zu der vorgenannten längeren Zeitskala der Öl-Alterung,
3. 3. Eine starke (zeitlich lokal) zeitlich beschränkte Steigungsänderung bedeutet regelmäßig einen Filtertausch. Ein Filtertausch, der also eine insofern vergleichsweise plötzliche, insbesondere zunehmende Trendabweichung zur Folge hat, erfolgt also auf sehr kurzer Zeitskala (praktisch instantan). Ein Filtertausch ist als praktisch instantane Trendabweichung erkennbar im Vergleich zu der vorgenannten kürzeren Zeitskala der Öl-Verdünnung. Während die beiden ersten Effekte einer Öl-Alterung und einer Öl-Verdünnung zu einer Verringerung der Viskosität führen, liegt der Unterschied bei diesen also in der Stärke, mit anderen Worten „Geschwindigkeit“, Rampe oder Steigung des Trends. D.h. während eine Viskositätsänderung bei einem normalen Motorbetrieb über hunderte von Stunden einer Betriebsdauer beobachtbar ist, tritt die Viskositätsänderung durch Öl-Verdünnung innerhalb weniger Stunden einer Betriebsdauer auf und ein Filtertausch ist in Bezug auf eine Gesamtskala einer Betriebsdauer im Vergleich dazu praktisch instantan. Ein Filtertausch wird jedenfalls bei einer vorgenannten ersten Variante (etwa bei einem Diesel- oder Otto-Motor) -regelmäßig aufgrund eines Tausches eines rußbeladenen Filters gegen einen freien Filter mit einer praktisch instantanen Abnahme der ÖlDruckdifferenz verbunden sein. Dies ist nicht notwendiger Weise der Fall bei einer vorgenannten zweiten Variante (etwa bei einem Gas-Motor), - regelmäßig liegt dort kein Tausch eines rußbeladenen Filters vor; gleichwohl kann es sich jedoch um einen zugesetzten Filter beim Tausch handeln.

During further training, it was recognized that when analyzing a relevant decreasing trend deviation from the current or previous trend development, three superimposed effects in particular must be taken into account. The training recognized that the causes of a decreasing trend deviation can be:

1. 1. Oil aging, which is recognizable as a decreasing trend deviation on a longer time scale (global in time),
2. 2. An oil dilution, which is also recognizable as a decreasing trend deviation (globally in time); with the advantage, however, on a significantly shorter time scale compared to the aforementioned longer time scale of oil aging,
3. 3. A strong (temporally local) time-limited change in gradient regularly means a filter change. A filter change, which therefore results in a comparatively sudden, particularly increasing trend deviation, takes place on a very short time scale (practically instantaneous). A filter change can be recognized as a practically instantaneous trend deviation in comparison to the aforementioned shorter time scale of oil dilution. While the first two effects of oil aging and oil dilution lead to a reduction in viscosity, the difference between these is the strength, in other words the "speed", ramp or gradient of the trend. This means that while a change in viscosity can be observed over hundreds of hours of normal engine operation, the change in viscosity due to oil dilution occurs within a few hours of operation and a filter change is practically instantaneous in comparison with the overall scale of an operating period. In any case, in the case of the first variant mentioned above (for example in a diesel or gasoline engine), a filter replacement will usually be associated with a practically instantaneous reduction in the oil pressure difference due to the exchange of a soot-laden filter for a free filter. This is not necessarily the case with the second variant mentioned above (for example in a gas engine), where there is usually no exchange of a soot-laden filter; however, the filter may be clogged when it is exchanged.

A “reset” of a trend observation after an oil or filter change has proven to be advantageous; this means that a temporal global trend analysis is then carried out with a new zero point for the trend analysis, for example with a regression curve or regression line.

According to a correspondingly preferred development, the further relational quantity value is analyzed as the relevant trend deviation in relation to a decreasing trend deviation from the trend development caused by at least one further relational quantity value, wherein according to the knowledge of the preferred development, a time extension and/or amplitude, in particular ramp, of the - in particular decreasing - trend deviation from the trend development is analyzed.

Preferably, it is provided that a trend signature of the decreasing trend deviation is recognized as the relevant trend development, for which the time extension, in particular ramp, has a finite value above zero and up to a maximum of several hours. In particular, the time extension is above 5 minutes and up to a maximum of ten hours.

In contrast, a differential pressure change occurs suddenly in the form of a sudden increase when oil is refilled. Refilling oil results in an increasing trend deviation. When the filter is changed, the differential pressure change occurs as a differential pressure drop; i.e. a decreasing trend deviation suddenly occurs - a subsequent oil refill results in a suddenly increasing trend deviation. This combination is particularly evident in the trend. These effects of an increasing differential pressure change are preferably ignored in a further analysis. However, any pressure jumps caused by an oil or filter change can be recognized and deducted from the trend (not described in detail here).

A particularly advantageous development of the method, in particular of a control and/or regulating device, relates to a determination of an oil condition of an operating oil for an engine of an internal combustion engine, in particular for a diesel or gas engine, preferably for detecting oil dilution.

It is advantageous to store a trend development of the relation size using a filter model.

A filter model for the oil filter can be designed in such a way that the processing of the first and second oil pressure takes place using a relational variable that takes the filter model into account in relation to an operating time and/or the operating parameters of the internal combustion engine. In particular, the above-mentioned trends of oil aging, oil dilution and filter replacement can be taken into account in the filter model in such a way that a distinction is made between a slow, faster and sudden trend.

In particular, it is intended that a relevant trend development of the relational quantity with respect to an oil dilution is discriminated by means of the filter model, in particular as a comparatively rapid but not sudden trend signature.

Advantageously, a trend development of the relational variable can also be stored with a filter model in such a way that when processing the first and second oil pressure using a relational variable that takes these into account in relation to an operating time of the internal combustion engine, a running-in period of the engine in the operating time and/or an oil refill are not taken into account and/or a filter change and, if necessary, an oil refill are followed by a new indication of the trend development. This avoids running-in periods and their relational variables distorting the otherwise robust determination of a trend development.

• - eine Einlaufzeit des Motors, wobei eine Trendsignatur einer Einlaufzeit im Trend bei der Betriebsdauer unberücksichtigt bleibt,
• - einen Filtertausch, wobei -gemäß dem oben genannten vierten Effekt-- eine abnehmende Trendsignatur des Filtertauschs im Trend von einer Neu-Angabe der Trendentwicklung gefolgt wird,
• - einer Öl-Alterung, wobei -gemäß dem oben genannten ersten Effekt-- eine abnehmende Trendsignatur der Öl-Alterung im Trend von einer ansteigenden Normal -Trendentwicklung überlagert wird,
• - einer Öl-Nachfüllung, wobei eine Trendsignatur der Öl-Nachfüllung -gemäß dem oben genannten zweiten Effekt-- plötzlich zunehmend oder moderat zunehmend ist.

Preferably, the relevant trend development of the relational variable is discriminated by means of the filter model concerning one or more trend signatures for:

• - a running-in period of the engine, whereby a trend signature of a running-in period is not taken into account in the trend for the operating time,
• - a filter change, whereby - in accordance with the fourth effect mentioned above - a decreasing trend signature of the filter change in the trend is followed by a new indication of the trend development,
• - an oil ageing, whereby - according to the first effect mentioned above - a decreasing trend signature of the oil ageing is superimposed by an increasing normal trend development,
• - an oil refill, where a trend signature of the oil refill is suddenly increasing or moderately increasing - according to the second effect mentioned above.

It is advantageous that the relational quantity takes into account the first and second oil pressure as an oil pressure difference.

The control and/or regulating device advantageously has a characteristic map module which is designed to form an oil pressure difference between the second and first oil pressure, in particular for an operating parameter and/or an operating time of the internal combustion engine. Preferably, a number of oil pressure difference values for an operating time for different operating parameters of the internal combustion engine are available in a characteristic map via the characteristic map module. It has therefore proven to be advantageous to generally form at least one oil pressure difference between the second and first oil pressure for each relational variable value at an operating time.

In particular, it is provided that for a point in time during operation, an oil pressure difference between the first and second oil pressure for a number of operating parameters of the internal combustion engine, i.e. for example engine parameters of the engine and/or oil parameters of the operating oil, is recorded in a characteristic map for the number of operating parameters; preferably, such a characteristic map can be stored in the characteristic map module.

Preferably, the operating parameters of the internal combustion engine include at least an engine speed of the engine and the oil temperature of the operating oil.

Preferably, the characteristic map is created for a standard engine and/or a standard operating oil. In this respect, the characteristic map can define a standardization standard for a standard engine and/or a standard operating oil. Different standards can also be defined that are specific to a certain engine type. For example, a standard can be defined for a mining engine for a few typically operating points; in contrast, a fracking engine will have a relatively "broad" characteristic map. It is advantageously provided that the oil pressure relation, in particular the oil differential pressure, in particular a first and second oil pressure, is converted to a standardized oil pressure relation, in particular to a standardized oil differential pressure.

For example, for each relation value at an operating time, a number of oil pressure relations of the second and first oil pressure, in particular the oil differential pressures of the second and first oil pressure, can be formed and a standardized relation value can be formed from an oil pressure relation, in particular oil differential pressure. Advantageously, for an operating time, the standardized relation value can be the quotient of the oil pressure relation, in particular the oil differential pressure, and an associated size of the characteristic map, in particular a Standard size, based on an operating parameter of the engine and/or oil parameter.

Within the scope of a preferred development, a standardized relational value for an oil pressure difference can be formed by means of a converter algorithm assigned to the engine to the standardized relational value for the operating time point in time; in particular, the converter algorithm can have a quotient, averaging and/or integration.

With regard to the trend deviation between the further relational quantity value and the trend development, a distance and/or gradient calculation is advantageously provided, in particular a difference quotient over time, by means of which the trend deviation is evaluated. In addition or alternatively, it is provided that in the event of a significant trend deviation, a status signal is output that indicates a significantly impaired oil condition. This has the advantage that a trend deviation between the further relational quantity value and the trend development can first be quantitatively evaluated before a status signal is output on the basis of this.

A trend deviation between the further relational size value and the trend development can be evaluated in different ways. In a first modified further development, a short-term trend development can be analyzed in such a way that the trend deviation of the further relational size value itself is analyzed from the normal trend development present at the time of operation.

In a second modified further development, a long-term trend development can be analyzed as particularly advantageous in such a way that a trend deviation of a trend development determined with the further relational quantity value from the normal trend development present at the time of operation is analyzed.

In addition, it has proven to be advantageous in the context of further training to specify an upper and lower limit development for a normal trend development and/or an earlier and later expected time for a status signal. The further training has recognized that specifying different trend developments at an upper and lower limit of a normal range makes specifying an expected time more reliable.

• - einen Betriebsaufzeichner, in dem eine Anzahl den zweiten und den ersten Öldruck berücksichtigende Relationsgrößen-Werte in Bezug auf eine Anzahl von Betriebsdauer-Zeitpunkten angegeben wird,
• - einen Trendbildner, mittels dem der Anzahl von Relationsgrößen-Werte eine Trendentwicklung zugeordnet wird,
• - einen Abweichungsbildner, mittels dem für einen weiteren zur Anzahl hinzutretenden Betriebsdauer-Zeitpunkt ein weiterer Relationsgrößen-Wert in Bezug auf eine vermittels wenigstens des einen weiteren Relationsgrößen-Wertes bewirkte Trendabweichung von der Trendentwicklung analysiert wird

Advantageously, the control and regulating device comprises an analysis module for the first and second oil pressure by means of a relational variable taking these into account in relation to an operating time of the internal combustion engine, which is designed to process the first and second oil pressure to convert it into a relational variable value that is independent of the operating parameter and has:

• - an operating recorder in which a number of relational values taking into account the second and the first oil pressure are specified in relation to a number of operating time points,
• - a trend generator, by means of which a trend development is assigned to the number of relational size values,
• - a deviation generator, by means of which a further relational quantity value is analyzed for a further operating time point in time added to the number in relation to a trend deviation from the trend development caused by at least one further relational quantity value

Preferably, the deviation generator is designed to evaluate the trend deviation and/or a signal generator is designed - in the event that the trend deviation is significant - to output a status signal that indicates a significantly impaired oil condition. A trend deviation can, for example, be evaluated for a regression trend curve of a changed trend development using a distance calculation for an amplitude; a trend deviation can also be evaluated additionally or alternatively and on a case-by-case basis, depending on the circumstances, using a difference quotient or differential quotient formation.

• 1 eine bevorzugte Ausführungsform einer Brennkraftmaschine mit vorliegend einem Diesel- oder Gasmotor, umfassend ein Ölleitsystem mit einem Ölfilter und mit einer Öl-Differenzdruck-Messeinrichtung;
• 2 eine Steuer- und Regeleinrichtung mit einer ECU und mit einem Kennfeldmodul und mit einem Analysemodul für die Brennkraftmaschine zur Umsetzung eines Verfahrens zum Erfassen eines Ölzustands eines Betriebsöls für einen Motor der Brennkraftmaschine gemäß einer bevorzugten Ausführungsform;
• 3 für ein Verfahren zum Erfassen eines Ölzustands eines Betriebsöls für einen Motor der Brennkraftmaschine in Ansicht (A) ein erstes Trendfeld T_a und in Ansicht (B) ein zweites Trendfeld T_b, jeweils zur Bestimmung einer Trendabweichung ΔT zwischen einem weiteren Relationsgrößen-Wert und einer bisherigen Trendentwicklung auf unterschiedliche Weise,
• 4 ein Ablaufdiagramm einer bevorzugten Ausführungsform des Verfahrens zum Erfassen eines Ölzustands eines Betriebsöls für einen Motor der Brennkraftmaschine wie in 1 mit einer Steuer- und Regeleinrichtung wie in 2 und unter Berücksichtigung einer Trendentwicklung wie in 3 erläutert;
• 5 eine schematische Darstellung für eine erste bevorzugte Ausführungsform betreffend die Wandlung gemessener Öldrücke zu einem Relationsgrößen-Wert, der unabhängig von einem Betriebsparameter ist, mittels eines Kennfelds und eines Wandleralgorithmus, wobei Relationsgrößen-Werte und eine Trendentwicklung in einem beispielhaften Trendfeld T_a über Betriebsdauer-Zeitpunkte dargestellt sind, für ein Verfahren zum Erfassen eines Ölzustands eines Betriebsöls für einen Motor der Brennkraftmaschine;
• 6 eine vergrößerte Darstellung des in 5 gezeigten Trendfeldes T_a mit einer vom Betriebsparameter unabhängigen Auftragung von Relationsgrößen-Werte als $\overline{\mathrm{\Delta }\text{p}}$
  
  über Betriebsdauer-Zeitpunkte h_i, i=1, 2, 3, sowie eine darauf basierende erste Trendentwicklung als obere Grenzentwicklung und eine zweite Trendentwicklung als untere Grenzentwicklung mit einem entsprechend früher bzw. später angesetzten Erwartungszeitpunkt für ein Zustandssignal;
• 7 eine schematische Darstellung für eine zweite besonders bevorzugte Ausführungsform für ein Verfahren zum Erfassen eines Ölzustands eines Betriebsöls für einen Motor der Brennkraftmaschine, wobei betreffend die Wandlung gemessener Öldrücke zu einem Relationsgrößen-Wert, der einen Betriebsparameter insofern berücksichtigt, dass in einer besonders bevorzugten Vorgehensweise mittels einem normierten Filter-Differenzdruck-Kennfeldder Filter-Differenzdruck normiert wird unter Erstellung eines normierten Filter-Differenzdruck, über die Betriebszeit, wobei Relationsgrößen-Werte als eine Trendentwicklung des normierten Filter-Differenzdrucks in einem beispielhaften Trendfeld T_a über Betriebsdauer-Zeitpunkte dargestellt sind;
• 8A zeigt beispielhaft einen konkreten Verlauf eines normierten Öl-Differenzdrucks $\overline{\mathrm{\Delta }\text{p}}$
  
  mit den zuvor genannten normierten Relationsgrößen-Werten R_i einer Trendentwicklung E über die Betriebsdauer h_B einer Brennkraftmaschine mit einem Motor und dem Ölfiltersystem;
• 8B in Ansichten (A) und (B) verschiedene Ausführungsformen von Trendfeldern T_a, T_b zur Bestimmung einer Trendabweichung ΔT zwischen einem weiteren Relationsgrößen-Wert und der Trendentwicklung; vorteilhaft im Rahmen einer in Ansicht (A) dargestellten langfristigen Trendentwicklung E_g zur Ermittlung von Filtertauschprognose oder einer in Ansicht (B) dargestellten kurzfristigen Trendentwicklung zur Erkennung von Öl-Verdünnung -E₁; in Ansicht (C) ist eine bevorzugte Variante zur Berücksichtigung eines Filtertauschs mit einer Filtertauscherkennung für ein Trendfeld, T_c dargestellt.

Embodiments of the invention are now described below with reference to the drawing in comparison to the prior art, some of which is also shown. This is not necessarily intended to show the embodiments to scale; rather, where useful for explanation, the drawing is in a schematic and/or slightly distorted form. With regard to additions to the teachings immediately apparent from the drawing, reference is made to the relevant prior art. It should be noted that a wide variety of modifications and changes can be made to the shape and detail of an embodiment without deviating from the general idea of the invention. The features of the invention disclosed in the description, the drawing and the claims can be essential for the development of the invention both individually and in any combination. In addition, all combinations of at least two of the features disclosed in the description, the drawing and/or the claims fall within the scope of the invention. The general My idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below or limited to an object that would be limited in comparison to the object claimed in the claims. In the case of specified dimensioning ranges, values within the stated limits should also be disclosed as limit values and can be used and claimed as desired. Further advantages, features and details of the invention emerge from the following description of the preferred embodiments and from the drawing, which shows in:

• 1 a preferred embodiment of an internal combustion engine with, in this case, a diesel or gas engine, comprising an oil guide system with an oil filter and with an oil differential pressure measuring device;
• 2 a control and regulating device with an ECU and with a characteristic map module and with an analysis module for the internal combustion engine for implementing a method for detecting an oil condition of an operating oil for an engine of the internal combustion engine according to a preferred embodiment;
• 3 for a method for detecting an oil condition of an operating oil for an engine of the internal combustion engine in view (A) a first trend field T _a and in view (B) a second trend field T _b , each for determining a trend deviation ΔT between a further relational quantity value and a previous trend development in different ways,
• 4 a flow chart of a preferred embodiment of the method for detecting an oil condition of an operating oil for an engine of the internal combustion engine as in 1 with a control and regulating device as in 2 and taking into account a trend development as in 3 explained;
• 5 a schematic representation of a first preferred embodiment relating to the conversion of measured oil pressures to a relational quantity value which is independent of an operating parameter, by means of a characteristic map and a converter algorithm, wherein relational quantity values and a trend development are shown in an exemplary trend field T _a over operating time points, for a method for detecting an oil condition of an operating oil for an engine of the internal combustion engine;
• 6 an enlarged view of the 5 shown trend field T _a with a plot of relational size values independent of the operating parameter as $\overline{\mathrm{\Delta }\text{p}}$
  
  over operating time points h _i , i=1, 2, 3, as well as a first trend development based thereon as an upper limit development and a second trend development as a lower limit development with a correspondingly earlier or later expected time for a status signal;
• 7 a schematic representation of a second particularly preferred embodiment of a method for detecting an oil condition of an operating oil for an engine of the internal combustion engine, wherein the conversion of measured oil pressures to a relational quantity value which takes into account an operating parameter in that, in a particularly preferred procedure, the filter differential pressure is normalized by means of a normalized filter differential pressure characteristic map, creating a normalized filter differential pressure over the operating time, wherein relational quantity values are shown as a trend development of the normalized filter differential pressure in an exemplary trend field T _a over operating time points;
• 8A shows an example of a concrete course of a standardized oil differential pressure $\overline{\mathrm{\Delta }\text{p}}$
  
  with the previously mentioned standardized relational quantity values R _i of a trend development E over the operating time h _B of an internal combustion engine with an engine and the oil filter system;
• 8B in views (A) and (B) different embodiments of trend fields T _a , T _b for determining a trend deviation ΔT between another relational quantity value and the trend development; advantageous in the context of a long-term trend development E _g shown in view (A) for determining filter replacement prognosis or a short-term trend development shown in view (B) for detecting oil dilution -E ₁ ; in view (C) a preferred variant for taking into account a filter replacement with a filter replacement detection for a trend field, T _c is shown.

1 shows an internal combustion engine 100 with an engine 101 and various structures such as air duct systems 102, comprising components such as turbochargers or the like, and furthermore heat exchangers 103, comprising coolers such as an air cooler or an oil cooler. The internal combustion engine also has an oil guide system 104, comprising an oil circuit with the oil cooler (not shown in detail) and an oil pan in which operating oil is guided, for example for lubricating bearings or seals of the engine. The oil guide system 104 also has one or more oil filter systems shown here, with an oil filter system 1 in the largest detail X of the 1 is shown. The oil filter system 1 has an oil filter 1F, which is designed in an oil line 1L, shown schematically here, for guiding operating oil 1B in the direction of flow. The oil filter system 1 also has an oil differential pressure measuring device 1M, comprising a first pressure sensor S1 arranged upstream of the oil filter 1F in the direction of flow and a second pressure sensor S2 arranged downstream of the oil filter 1F in the direction of flow. The first pressure sensor S1 is used to detect and indicate a first oil pressure p1 upstream of the oil filter 1F and the second pressure sensor S2 is used to detect and indicate a second oil pressure p2 downstream of the oil filter 1F.

The first and second oil pressures p1, p2 are merely examples of a number of oil pressures that can be recorded with corresponding pressure values from the first and second pressure sensors S1, S2 and possibly further pressure sensors before, after or on the filter 1F. The oil supply system 104 can also have a number of oil filter systems with one or more oil filters, of which only one oil filter system 1 is shown schematically here as an example. In this respect, the particularly preferred embodiment described here is not limited to the design with a single oil filter system 1, but can be implemented at several points on the oil supply system 104 by means of a number of oil filter systems 1. In the present case, the first and second oil pressures p1, p2 are fed to a 2 The control and regulating device 10 shown in more detail -- also called "device for controlling and regulating 10" -- of the internal combustion engine 100. The internal combustion engine 100 has, among other things, a 1 The engine control unit “Engine Control Unit” (ECU) 10 shown here is activated.

The in 2 The control and regulating device 10 shown is only shown schematically with regard to its functionality and does not limit its implementation as a system or structural unit; rather, this control and regulating device 10 can be implemented in part or in its entirety on a vehicle or networked with a vehicle. In addition to the actual engine control unit ECU, the control and regulating device 10 comprises a schematically shown map module 10.1 and an analysis module 10.2; with the exception of a sensor system S, these can but do not have to be part of the engine control unit ECU - in a preferred embodiment, the units explained below are part of the engine control unit ECU with the exception of a sensor system S.

The sensor system S is assigned to the map module 10.1 (e.g. with the aforementioned pressure sensors S1, S2) for determining operating parameters BP of the internal combustion engine and other sensor data D. The operating parameters BP can include, for example, the engine operating parameters MOT _S and oil parameters Oil _S mentioned here. Part of the sensor system S is, for example, the oil differential pressure measuring device 1M explained above as an example with the first and second pressure sensors S1, S2; this supplies the oil pressures p1, p2 already mentioned.

Furthermore, the sensor system of the sensor system S, which is oriented towards the operating oil, includes an oil temperature sensor for determining an oil temperature T _oil . Furthermore, the sensor system of the sensor system S includes engine sensors, for example on the crankshaft of the engine in the area of reference number 101 for determining an engine speed n _MOT and various other performance-related engine data, such as an engine torque M _{MOT (} not shown here), an engine temperature, a coolant flow rate or the like; this can also include load queries and other performance data or vitality data of the engine.

und dann zu den Zeitpunkten hi in das Trendfeld T_a gespeichert werden.How to continue 2 As can be seen, the engine operating parameters MOT _S and the oil parameters Öl _S , the engine speed n _MOT and the operating time h _B of the engine can be determined by means of appropriate sensors as part of the sensor data D; these are shown here only as examples as part of the sensor data D in 2 shown. Such and other sensor data D can be summarized in one or more characteristic maps K in the characteristic map module 10.1 and stored for example for pre-control of the internal combustion engine or the motor in the characteristic map module 10.1 as part of the control and regulating device 10; the characteristic map module 10.1 is preferably housed in the structural unit of the engine control unit ECU. In particular, the characteristic map can be stored there as a standard characteristic map in the characteristic map module 10.1, in which standard pressures or standard differential pressures for a standard engine and/or a standard operating oil are stored in relation to a number of operating parameters MOTs of the engine and/or oil parameters _S of the operating oil. The characteristic map K is preferably learned at the beginning of the engine's life and then represents a reference for standardizing all future measured values Δpi. Above all, pressure values for oil differential pressures Δp _i in the converter module W that accumulate during operation can be standardized using the characteristic map K. Oil differential pressures Δp _i can be divided by standard differential pressures of the characteristic map K and/or averaged to $\overline{\mathrm{\Delta }\text{p}}$

and then stored in the trend field T _a at the times hi.

Exemplary of the present preferred embodiment is shown in 2 A characteristic map K is shown symbolically, in which on an X-axis a Engine parameter MOT _S -- namely here the engine speed n _MOT -- is shown and on the Y-axis an oil parameter oil _S -- namely in this case the oil temperature T _oil -- is shown. In particular, a standard characteristic map K of standard differential pressures for a standard engine and/or a standard operating oil can be created in this way in relation to a number of operating parameters B of the engine and/or oil parameters of the operating oil. For such operating parameters B = (T _oil , n _MOT ) that can be represented in the system, a relational variable R which takes the first and second oil pressure into account is also shown here; this in turn can be recorded during operation of the specific engine. The relational variable R is recorded here as the oil pressure difference between the second oil pressure and the first oil pressure during operation of the specific engine and is shown here as the oil pressure difference Δp = p2 - p1.

The three-dimensional standard map K used here as an example can also be more complex or comprehensive and is available to the engine control unit ECU; for this purpose, the standard map K is stored in the engine control unit as explained; however, it can also be available remotely, for example, it can be called up by the ECU from a control center.

In 2 To this end, it is first shown schematically that a relational quantity R that takes oil pressures into account is used for a number of oil parameters and a number of engine parameters MOTs. This means that for several or further operating parameters B, a relational quantity R is plotted in a standardization map K (standard map), whereby the difference between the second oil pressure and the first oil pressure when operating a healthy engine with new oil and new filter is recorded as the relational quantity R as a function of oil temperature and speed.

A relational quantity R taking into account the oil differential pressure Δp _i or a standardized relational quantity value R can in any case be calculated in different ways from the oil pressures.

The present embodiment provides a standardization map K of standard differential pressures Δp_norm i or. This indicates normal differential pressures Δp_norm i or at least normal pressures (p1, p2)_norm of a healthy engine with new oil and new filter depending on oil temperature and speed. It is used to calculate the actual measured values p1, p2 or the actually measured oil differential pressure (p2-p1)=Δpi=f (oil temp, engine speed) in a 2 to standardize the trend field T shown on the right in such a way that it is independent of the oil temperature and the engine speed - this can be achieved most easily by division, in which, for example, the oil differential pressure (p2-p1)=Δpi formed from the actual measured values p1, p2 is divided by the difference in the normal pressures (p1, p2)_norm. In general terms, a number of relational quantity values (R ₁ , R ₂ , R ₃ , R _i ) taking the oil differential pressure Δp _i into account are converted using the standard characteristic field K to a standardized relational quantity value R, i.e. into standardized dimensionless values Ri.

In a variation, there may also be a characteristic map of standard pressures p_norm i, which is not shown in more detail. This then represents normal pressures p_norm i of a healthy engine with new oil and new filter as a function of oil temperature and speed. The measured oil pressures can be recorded in a characteristic map K for the oil pressure relationship, in particular the oil differential pressure, in relation to a number of operating parameters B of the engine and/or oil parameters of the operating oil - from this, the oil pressure relationship, in particular the oil differential pressure, in relation to a number of operating parameters B of the engine and/or oil parameters of the operating oil can be determined and recorded in a characteristic map K.

(hier $\overline{\mathrm{\Delta }\text{p}}\_\text{norm}$

der als normierter Öl-Differenzdruck die Betriebsparameter B berücksichtigt, zu denen der Öl-Differenzdruck gemessen wurde, der aber unabhängig vom Betriebsparameter B ist.In detail, a trend field T --as shown schematically in 2 indicated on the right-- in 3 with two examples of a trend. For the purpose of the present embodiment, an oil pressure difference Δp measured via the oil filter 1F is plotted against an oil temperature T _oil and an engine speed n _MOT - in this case, the relational quantity R is therefore given directly by the oil pressure difference Δp measured via the oil filter 1F; in principle, however, another type of relational quantity is also conceivable, e.g. a quotient. In most cases, it has also proven advantageous to use such a standardization map K -- comprehensively taking oil pressure into account relational quantities R -- to form an above-mentioned Δp_norm, ie for example -- to be converted via oil parameters oils and engine parameters MOT _S to a relational quantity value $\overline{\mathrm{\Delta }\text{p}}$

(here $\overline{\mathrm{\Delta }\text{p}}\_\text{standard}$

which, as a standardized oil differential pressure, takes into account the operating parameters B for which the oil differential pressure was measured, but which is independent of the operating parameter B.

The conversion is carried out using a converter algorithm A in a converter module W as part of an analysis module 10.2. The converter module W operates a converter algorithm A, which uses the map data Δp_norm of the map K _NORM , with the help of the operating parameters B of the engine speed n _MOT and the oil temperature T _Oil ; in this case to standardize the measured oil pressure difference Δp and to use a division to calculate the standardized value R. The details of such a converter algorithm A can be formed expediently and individually for the internal combustion engine 100. 3 shows in view (A) a first trend field T _a and in view (B) a second trend field T _b , each for determining a trend deviation ΔT between another relational quantity value and a previous trend development in different ways. A trend development is basically any recognizable and, if necessary, mathematically interpolatable or otherwise comprehensible mathematically analyzed indication of a development of the relational quantity values over the operating time periods.

In the present case, a trend development over the operating time points is given by specifying an interpolating compensation curve for the relational quantity values over the operating time points, namely as a regression line of the 3 based on the least squares method. In particular, a trend can include the indication of a slope of the interpolating best fit curve, namely the regression line in this case, or a trend development can include the indication of an interpolating - and possibly extrapolating - best fit curve, namely the regression line in this case.

In the context of a further development already mentioned here, it has been shown that a trend development up to a certain operating time can be referred to as a normal trend development. In the present case, a normal trend development is to be understood as any expected trend development without a change in the oil condition in the narrower sense, with which a comparison is made for a further operating time in addition to the number of operating time points; namely in order to determine a relevant trend deviation ΔTg, ΔTe caused by the at least one further relational quantity value from the trend development existing up to that point, in particular the trend development referred to as a normal trend development.

In the context of a further development specified here, it is advantageous to assume a certain normal trend development under certain conditions; e.g. if one assumes the behavior of an engine that does not show any change in the oil condition in the narrower sense. In a first variant of a further development explained here, an overall increasing trend TK1 of the 3 in the behavior of an oil differential pressure or similar oil pressure relation. In a second variant of a further development - for example primarily in a gas engine - a constant or decreasing trend of an oil differential pressure or similar oil pressure relation can be assumed. Both variants are explained below. Further reference to 3 with a first trend field T _a within the framework of a long-term trend development E _g - i.e. a trend development E _g on a rather longer time scale, in particular a range of 100 to 500 or 1000 operating hours - or with a second trend field T _b within the framework of a short-term trend development E ₁ - i.e. a trend development E ₁ on a rather shorter time scale, in particular in the range of perhaps 0.5 to 1 or 10 operating hours, in particular in the hourly range - for a further operating time point hi added to the number of operating time points hi, a further relational quantity value R _i+1 is analysed as a decreasing trend deviation in relation to a relevant trend deviation ΔT from the trend development E caused by at least one further relational quantity value R _i+1 .

In a particularly preferred embodiment, the trend T in the present case comprises in particular an indication of a slope in the trend field T _a and trend field T _b ; specifically, the development of a slope of a trend curve TK1, TK2, TK 3 can be recorded for this purpose.

der Öldruck-Differenzen Δp-- in Bezug gesetzt ist zu einem Verlauf über die Betriebsdauer h_B bzw. einer entsprechenden Anzahl von Betriebs-Zeitpunkten h_i, i=1, 2, 3 deren Werte im Weiteren mit Z₁, Z₂, und Z₃ angegeben sind.In 3 it is shown that the operating parameter-independent relational quantity R, present with relational quantity values R ₁ , R ₂ , R _{3 ,} is based on the number of oil pressure differences Δp, which were standardized with the standardization map K for various operating parameters B and determined at an operating time h _i , i=1, 2, 3; the values of the operating time h _i , i=1, 2, 3 are referred to below with Z ₁ , Z ₂ , and Z ₃ . The operating parameter-independent relational quantity value R is referred to as the standardized differential pressure Δp_norm_i -- as in relation to 3 explained in more detail-- into a trend field T. In a real case, the trend field T is available as a data set in which the operating parameters are independent relational variables R --here the values of the standardized (and possibly also integrated) mean values $\overline{\mathrm{\Delta }\text{p}}$

the oil pressure differences Δp-- are related to a curve over the operating time h _B or a corresponding number of operating times h _i , i=1, 2, 3 whose values are given below as Z ₁ , Z ₂ , and Z ₃ .

The control and regulating device 10 according to the 2 Thus, in addition to the sensor system S for detecting engine parameters MOT _S and oil parameters Oil _S, it comprises one or more characteristic maps K for normalizing the oil pressure differences Δp or other relational quantities R for an operating time h _i , i=1, 2, 3 in the operating time h _B and for different operating parameters B of the internal combustion engine.

der Öldruck-Differenzen Δp. Eine Mittelung ist zwar insofern sinnvoll; aber wenn der Rohwert Δp mit R verrechnet wird ist hier vor allem von einem zunächst normierten Wert auszugehen, der wie in oben erläuterter Weise zunächst als unabhängig von den Betriebsparametern des entsprechenden Betriebspunktes angesehen werden kann. $\overline{\mathrm{\Delta }\text{p}}$

kann dann dann zudem ein normierter Mittelwert sein.Using a converter module W mentioned above and a corresponding conversion algorithm A, it is possible to store a history of operating parameter-independent relational variable values R _i over a time axis; in this case, these are the mean values standardized using Δp_norm $\overline{\mathrm{\Delta }\text{p}}$

the oil pressure differences Δp. Averaging is indeed useful in this respect; however, when the raw value Δp is offset against R, it is primarily a standardized value that must be assumed, which, as explained above, can initially be regarded as independent of the operating parameters of the corresponding operating point. $\overline{\mathrm{\Delta }\text{p}}$

can then also be a standardized mean.

3 shows exemplary trend fields, namely in view (A) a first example of such a trend field T _a and in view (B) a second example of such a trend field T _b .

als eine Trendentwicklung E angegeben. Eine Trendentwicklung E ist hier für das Trendfeld T_a als langfristige Trendentwicklung E_g bezeichnet. Die langfristige Trendentwicklung E_g zeichnet sich vorliegend durch eine obere und untere Grenzentwicklung G_o und G_u aus. Auf diese Weise kommt für jeden vorhandenen und dann hinzutretenden Relationsgrößen-Wert R₁, R₂, R₃ -also zuletzt der Relationsgrößen-Wert R3-- eine so bezeichnete erste, d. h. bisherige, Trendkurve TK1 heraus, die vorliegend an der oberen Grenzentwicklung G_o liegt.Für den in der Ansicht (a) der 3 im ersten Trendfeld T_a dann anschließend, weiteren hinzutretenden Betriebsdauer-Zeitpunkt bei h_i ist vorliegend ein weiterer Relationsgrößen-Wert R_i eingetragen und als Ergebnis einer kumulativen Betrachtung von R₁, R₂, R₃ ... R_i usw. für Zeitpunkt-Werte Z₁, Z₂, Z₃ .... Z_i usw. ist eine zweite, d. h. weitere, Trendkurve TK2 angebbar. Dies führt zu einer Trendabweichung ΔT, die im Wesentlichen mit einer langfristigen Trendabweichung ΔTg messbar ist und die sich von der bisherigen Trendentwicklung zwischen den Grenzentwicklungen G_o, G_u erkennbar abhebt; d. h. die aus dem durch sie begrenzten Vertrauensbereich T_B herausfällt. Genau genommen ist aber die Trendkurve TK1 in Ansicht (A) im langfristigen Trend mit hinzugefügten R1, R2, R3 streng genommen nicht mehr linear; eine weitere Möglichkeit zur Bestimmung einer langfristigen Trenderkennung umfasst deswegen zum Beispiel eine lineare Regression, die auch für eine Extrapolation genutzt werden kann.In 3 Example (A) is a relational quantity R independent of the operating parameter plotted over the operating time h _B (e.g. in operating hours) of an internal combustion engine 100, ie for a number of operating time points h _i , i=1, 2, 3, a number of operating parameter independent relational quantity values R ₁ , R ₂ , R ₃ ... R _i are shown and for the number of relational quantity values R ₁ , R ₂ , R ₃ ... R _i, respectively assigned operating quantity values are $\overline{\mathrm{\Delta }\text{p}}$

as a trend development E. A trend development E is referred to here as a long-term trend development E _g for the trend field T _a . The long-term trend development E _g is characterized in this case by an upper and lower limit development G _o and G _u . In this way, for each existing and then added relational value value R ₁ , R ₂ , R ₃ - thus finally the relational value value R3 - a so-called first, ie previous, trend curve TK1 is produced, which in this case lies at the upper limit development G _o. For the trend curve shown in view (a) of the 3 in the first trend field T _a then, subsequently, for the further added operating time point in time at h _i, a further relational quantity value R _i is entered and as a result of a cumulative consideration of R ₁ , R ₂ , R ₃ ... R _i etc. for time values Z ₁ , Z ₂ , Z ₃ .... Z _i etc. a second, i.e. further, trend curve TK2 can be specified. This leads to a trend deviation ΔT which can essentially be measured with a long-term trend deviation ΔTg and which clearly stands out from the previous trend development between the limit developments G _o , G _u ; i.e. which falls outside the confidence interval T _B delimited by it. Strictly speaking, however, the trend curve TK1 in view (A) is no longer linear in the long-term trend with added R1, R2, R3; another possibility for determining a long-term trend detection therefore includes, for example, linear regression, which can also be used for extrapolation.

This type or any other appropriate way of determining that a further trend curve TK2 clearly falls outside the confidence interval T _B of previous trend curves TK1 is referred to here as an evaluation of a long-term trend development E _g .

der Öldruck-Differenz Δp = p2 - p1 zugeordnet ist.In 3 Example (B) shows a so-called short-term trend development E ₁ . Again, relational size values R ₁ , R ₂ , R ₃ and R _i are given for operating time points h _i , i=1, 2, 3, whereby each relational size value R _i , i=1, 2, 3 is assigned an averaged integrated operating size value $\overline{\mathrm{\Delta }\text{p}}$

the oil pressure difference Δp = p2 - p1.

In this second trend field T _b it is evident that the further relational value R _i deviates significantly from the previous trend curve TK1 of the trend field T _b and the local trend deviation ΔT ₁ can - as already in the distance calculation for the long-term trend development E _g in 3(A) -- be evaluated by means of a distance calculation, in particular a difference calculation, in the coordinate system described above. This type of distance calculation for a local trend deviation ΔT ₁ is referred to here as an evaluation of a short-term trend development E _1. In particular, a short-term trend, like a long-term trend, can be calculated using a difference quotient in the sense of a slope of the trend curve; ie in the sense of trend T = ΔR/Δt = (Ri-R3) / (hj-h3); a differential quotient is also possible; in these cases the measured values do not have to be equidistant.

In both examples (A) and (B) of the 3 a significant trend deviation ΔT can be identified in the trend field T _a or T _b . In example (a) in the trend field T _a the trend deviation ΔT is recognizable as a global trend deviation ΔT _g in that a further trend curve TK2 clearly falls outside the confidence interval T _B of previous trend curves TK1. In example (b) in the trend field T _b the trend deviation ΔT is recognizable as a local trend deviation ΔT ₁ in that the distance of a further relational quantity value R _i from the previous trend curve TK1 is significantly greater than before, ie the relational quantity value R _i deviates very clearly from the previous trend curve TK1. One could also determine that a further trend curve TK3 is no longer linear.

As a result, the preferred embodiment provides that on the basis of such a representation of relational quantity values R ₁ , R ₂ , R ₃ independent of the operating parameter B of an engine and an analysis of trend developments E _g or E ₁ based thereon (in this case by means of the trend fields T _a , T _b and a corresponding developing trend curve TK), a trend deviation ΔT is determined, for example as in 3A or 3B shown global trend deviation ΔT _g or local trend deviation ΔT ₁ . A trend deviation ΔT can then be used as an indicator for an oil condition and a change in the same. The oil condition is therefore determined on a very reliable model of an oil pressure difference Δp or oil pressure differences Δp _i via the oil filter 1F that takes all operating parameters of the internal combustion engine into account. It has been shown that if a trend deviation ΔT (e.g. the previously explained global or local trend deviation ΔT _g or ΔT ₁ ) is significant, a condition signal can be output that can indicate a significantly impaired oil condition.

Such a procedure is shown schematically in 4 shown with a flow chart. In a first step V1, test conditions and resets can be implemented which are intended to make the measurements and evaluations reliable and in particular to avoid falsifications; examples of such test conditions and resets are given in relation to 8C explained. For example, the history of an oil filter 1F can be taken into account. A zero point adjustment of the two pressure sensors can also be carried out in the "engine STOPPING" operating state in order to exclude offset errors of the sensors.

In a step V2, operating parameters of the engine and the oil can be measured via an oil filter 1F; in this case, for example, the engine speed n _MOT and the oil temperature T _Oil are measured - in addition, there is an oil pressure difference Δp _i determined on the basis of the oil pressures p1, p2 at a specific operating time and the operating time h _B of the internal combustion engine, which is also measured in 2 are shown.

As a result, in a step V3, a characteristic map K of the internal combustion engine can plot the operating parameters BP of the aforementioned type and the oil pressure difference Δp _i for a number of operating time points h _i , i=1, 2, 3, for example as a possible relational variable R _i for a number of operating time points h _i , i=1, 2, 3 and the operating time h _B to one another.

angegeben ist; d. h. die abhängig von der Anzahl von Öldruckdifferenzen ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

ist (Δp_i zeitlich gefiltert, gemittelt, summiert oder aufintegriert über alle Betriebszustände zu einem Betriebsdauer-Zeitpunkt h_i) und abhängig ist von einer Betriebsdauer h_B der Brennkraftmaschine. Die zuvor erläuterte Trendabweichung ΔT kann beispielsweise hinsichtlich einer Signifikanz analysiert werden in einem Analysemodul 10.2 im Schritt V6 wie dies anhand von 3 erläutert wurde. Als Beispiel ist hier etwa eine Schwellwertprüfung der Trendabweichung ΔT oder des Trends T möglich, in welcher ermittelt wird, ob eine Trendabweichung (im Vergleich zu einem bestehenden Trend im Rahmen einer Trendänderung) einen vorbestimmten Schwellwert SW überschreitet; dies kann vor allem eine Abweichung eines Absolutwerts betreffen aber auch eine Abweichung eines Steigungswertes. Die Trendabweichung entsteht insofern vor allem infolge eines weiteren Relationsgrößen-Wertes sodass eine weitere Trendentwicklung von einer bisherigen Trendentwicklung E abweicht. Die Trendabweichung ΔT kann auf Basis einer langfristigen oder kurzfristigen Trendabweichung ΔT_g oder ΔT₁ bestimmt werden wie dies anhand von 3 erläutert wurde. In einem Schritt V7 kann die Trendabweichung ΔT untersucht werden hinsichtlich des Vorzeichens. Dazu wird über die Abfrage „ΔT < 0“ im Rahmen einer Abweichungsprüfung im Schritt V8 konkretisiert, ob eine Trendabweichung ΔT unter Null liegt. Ist dies der Fall kann auf eine Öl-Verdünnung geschlossen werden. Ist die Trendabweichung ΔT nämlich negativ --d. h. liegt ΔT unterhalb von null-- kann in einem Schritt V9 auf eine Öl-Verdünnung geschlossen werden. Zur Verbesserung einer Robustheit des Verfahrens kann neben dem globalen (insofern langfristigen) Trend vor allem auch der lokale (insofern kurzfristige) Trend für die Erkennung der Ölverdünnung verwendet werden. Wenn T beispielsweise in der oben erwähnten Weise als Steigungswert interpretiert wird ist eine Trendabweichung ΔT kleiner null wenn die entsprechende Trendkurve im Sinne einer geänderten Trendentwicklung nach unten abknickt. In einer ersten Ausführung kann hier der erwähnte Absolutwert der Amplitude aber auch zusätzlich oder alternativ ein Absolutwert einer Steigung überwacht werden. Dazu kann beispielsweise eine konkrete Schwelle kleiner S1 angegeben und überwacht werden mittels der Abfrage T<S 1.Such a characteristic map K can be converted in a fourth step V4 by means of a corresponding converter algorithm A to represent a trend development T. The step V4 can be carried out, for example, by means of a 2 schematically shown analysis module 10.2 and converter module W(A). A converter algorithm A is based on a number of relational size values R _i , relating to the oil pressure difference Δp _i at the operating time points h _i , i=1, 2, 3 and the operating time h _B . Here, this includes in particular a trend curve TK, which in step V5 is a function $\text{T}\left({\overline{\mathrm{\Delta }\text{p}}}_{\text{i}},{\text{h}}_{\text{B}}\right)$

is specified; ie depending on the number of oil pressure differences ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

is (Δp _i temporally filtered, averaged, summed or integrated over all operating states at an operating time h _i ) and is dependent on an operating time h _B of the internal combustion engine. The previously explained trend deviation ΔT can be analyzed for significance in an analysis module 10.2 in step V6, for example, as shown in 3 As an example, a threshold value test of the trend deviation ΔT or the trend T is possible, in which it is determined whether a trend deviation (in comparison to an existing trend in the context of a trend change) exceeds a predetermined threshold value SW; this can primarily concern a deviation of an absolute value but also a deviation of a gradient value. The trend deviation arises primarily as a result of another relational value so that a further trend development deviates from a previous trend development E. The trend deviation ΔT can be determined on the basis of a long-term or short-term trend deviation ΔT _g or ΔT ₁ as is the case with 3 explained. In step V7, the trend deviation ΔT can be examined with regard to its sign. To do this, the query “ΔT < 0” is used as part of a deviation test in step V8 to specify whether a trend deviation ΔT is below zero. If this is the case, oil dilution can be concluded. If the trend deviation ΔT is negative - i.e. ΔT is below zero - oil dilution can be concluded in step V9. To improve the robustness of the method, in addition to the global (i.e. long-term) trend, the local (i.e. short-term) trend can also be used to detect oil dilution. If T is interpreted as a gradient value in the manner mentioned above, for example, a trend deviation ΔT is less than zero if the corresponding trend curve bends downwards in the sense of a changed trend development. In a first embodiment, the aforementioned absolute value of the amplitude can be monitored here, but also additionally or alternatively an absolute value of a gradient. For example, a concrete threshold smaller than S1 can be specified and monitored using the query T<S1.

In a variation, it is also possible to monitor the trends directly for limit values. For example, a query S1<T<S2 can be used to check whether oil dilution is present if the trend T falls outside the acceptable range [S1, S2]. A query S1>T can also be used to check whether a filter change is necessary.

The embodiment has recognized that oil dilution can be caused by diesel fuel or cooling water entering the oil circuit and which represents the decisive process sequence. This results in the loss of lubricity and a corresponding reduction in viscosity.

über einen Filter annehmen könnte; d. h. die Voraussetzung, dass der Differenzdruck Δp_i über die Betriebsdauer-Zeitpunkte h_i, i=1, 2, 3 streng monoton zunimmt basiert auf der Annahme, dass sich bei einer Rußentwicklung eines Diesel- oder Otto-Motors ein Filter normalerweise zunehmend zusetzt und damit seinen Differenzdruck Δp_i erhöht. Das Konzept der Erfindung sieht dazu vor, dass die Anzahl von Relationsgrößen-Werte R₁, R₂, R₃... R_i --wie zuvor erläutert wurde-- einer Trendentwicklung E über die Betriebsdauer-Zeitpunkte hi zugeordnet wird; daraus ist regelmäßig auch eine Art Normal-Trendentwicklung für den bestimmten Motor oder Motortyp erkennbar wie hier einem Diesel- oder Otto-Motor.This is particularly evident in comparison to a normal trend development, if one considers a fundamentally strictly monotonic course of a trend development E of a differential pressure under certain circumstances and for a certain engine (e.g. diesel or gasoline engine). ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

across a filter; i.e. the requirement that the differential pressure Δp _i increases strictly monotonically over the operating time points h _i , i=1, 2, 3 is based on the assumption that when soot is produced in a diesel or Otto engine, a filter normally becomes increasingly clogged and thus increases its differential pressure Δp _i . The concept of the invention provides for the number of relational quantity values R ₁ , R ₂ , R ₃ ... R _i -- as previously explained -- to be assigned to a trend development E over the operating time points hi; from this, a type of normal trend development can regularly be identified for the specific engine or engine type, such as a diesel or Otto engine here.

in Betracht kommen. Ein entsprechend abgewandelter Ablauf für einen Gasmotor könnte umfassen:

• - im Schritt V2
  • - Bilden von Δp_i über den Öldruck
  • - Glätten (z.B. über einen Zeitfilter) von Δp_i Öldruck zu ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$
    
• - im Schritt V5
  • - Normieren des Öl-Differenzdrucks und Darstellen als Relationsgröße $\text{R}={\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}\text{/}\mathrm{\Delta }\text{p}\_\text{norm}$
    
  • - Bilden einer Trendaussage auf Basis eines Differenzen- oder Differential-Quotienten Ti = (Ri - Ri-1)/ (hi-hi-1)
• - im Schritt V6 bis V8 $$\text{S}$$$$1<\text{T}<\text{<figure-callout id="2" label="S" filenames="DE102020126900B4\_0045.png" state="{{state}}">S</figure-callout>}2$$
  
  - wenn ja, Ölverdünnung $$\text{T}<\text{<figure-callout id="1" label="S" filenames="DE102020126900B4\_0049.png,DE102020126900B4\_0050.png" state="{{state}}">S</figure-callout>}1$$
  
  - wenn ja, Filtertausch

The monotonous increase in differential pressure is not normally present in gas engines, as these do not produce soot. This means that the aforementioned query V6, which applies primarily to diesel or gasoline engines, does not always indicate oil dilution. This would also be apparent in a gas engine if the number of relational variable values R ₁ , R ₂ , R ₃ , R _i -- as previously explained -- is assigned to a trend development E over the operating time points hi; this regularly also reveals a type of normal trend development for the specific engine or engine type, such as a gas engine here. Then, in the flow chart of the process, the 4 in modification of query V6 of the 4 Queries on absolute gradient limits or gradient changes are more effective. For example, the query $$\begin{array}{l}\text{slope T}<\text{<figure-callout id="1" label="threshold" filenames="DE102020126900B4\_0049.png,DE102020126900B4\_0050.png" state="{{state}}">threshold</figure-callout>}1=\ddot{\text{O}}\text{lverd}\ddot{\text{u}}\text{nnung}\hfill \\ \text{slope T}<\text{<figure-callout id="2" label="threshold" filenames="DE102020126900B4\_0045.png" state="{{state}}">threshold</figure-callout>}2=\text{filter replacement}\hfill \end{array}$$

A correspondingly modified process for a gas engine could include:

• - in step V2
  • - Formation of Δp_i via the oil pressure
  • - Smoothing (e.g. via a time filter) of Δp_i oil pressure to ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$
    
• - in step V5
  • - Normalizing the oil differential pressure and displaying it as a relational quantity $\text{R}={\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}\text{/}\mathrm{\Delta }\text{p}\_\text{standard}$
    
  • - Forming a trend statement based on a difference or differential quotient Ti = (Ri - Ri-1)/ (hi-hi-1)
• - in steps V6 to V8 $$\text{S}$$$$1<\text{T}<\text{<figure-callout id="2" label="S" filenames="DE102020126900B4\_0045.png" state="{{state}}">S</figure-callout>}2$$
  
  - if yes, oil dilution $$\text{T}<\text{<figure-callout id="1" label="S" filenames="DE102020126900B4\_0049.png,DE102020126900B4\_0050.png" state="{{state}}">S</figure-callout>}1$$
  
  - if yes, filter replacement

A trend development E of the relational quantity R with a filter model demonstrates this processing of the first and second oil pressure by means of a relational quantity taking these into account in relation to an operating time h _B of the internal combustion engine (e.g. specified in operating hours). 5 shows a schematic representation of a first preferred embodiment relating to the conversion of measured oil pressures to a relational quantity value that is independent of an operating parameter, using a characteristic map and a converter algorithm. This is a comparatively sophisticated approach. Relational quantity values and a trend development are shown in an exemplary trend field T _a over operating time points, for a method for detecting an oil condition of an operating oil for an engine of the internal combustion engine.

5 shows on the left the relational variable values R ₁ , R ₂ , R ₃ resulting from the test or pre-operation of an internal combustion engine at operating time points h _i , i=1, 2, 3 whose values are given here as Z ₁ , Z ₂ and Z ₃ . These are assigned, as an example, learned differential pressures as relational variable values R ₁ , R ₂ , R ₃ in the characteristic map K of operating parameters B, namely an engine parameter and oil parameter, namely in this case engine speed n _MOT and oil temperature T _Oil . In this way, a standard characteristic map K of standard differential pressures can be created for a standard engine and/or a standard operating oil in relation to a number of operating parameters B of the engine and/or oil parameters of the operating oil. The learning of the standard characteristic map preferably takes place in the first operating hours when the filter and oil are still new. This saves the individual behavior of this machine when it was new. In a modification or addition to this procedure, the standard map can also be pre-initialized with empirical values or finalized.

R _i therefore stands for a matrix of relational quantities R _i (n _MOT , T _Oil ). In this case, the relational quantity values R _i for i=1, 2, 3 ... n of this matrix are specified for certain operating parameters B, whereby a relational quantity value R _i represents an oil pressure difference p2 - p1 = Δp _i across the previously explained filter 1F for a certain operating parameter B.

The converter module W now executes a converter algorithm A which uses all operating parameters B, i.e. in this case the oil pressure difference Δp as they result from the real operation of an internal combustion engine to specify relational quantity values R ₁ , R ₂ , R ₃ at operating time points h _i , i=1, 2, 3 in actual operation, normalized to one or the respective operating parameters B, i.e., for example, averaged or divided or integrated over the operating parameters B or the oil pressure difference Δp otherwise normalized in relation to the operating parameters B. A "normalization" to be understood generally in this sense can therefore include averaging or integration and/or a quotient formation, in each case for one of the operating time points h _i , i=1, 2, 3, the value of which is specified here as Z ₁ , Z ₂ and Z ₃ (here, for example, for Z ₁ , Z ₂ , Z ₃ etc.).

für Zeitpunkte hi in der Betriebsdauer h_B der Brennkraftmaschine ab, was in 2 rechts dargestellt ist.The integration takes into account, where appropriate, weightings, frequencies and priorities of the oil and engine parameters mentioned (oil, MOTs) and forms a weighted integrated mean value $\overline{\mathrm{\Delta }\text{p}}$

for times hi in the operating time h _B of the internal combustion engine, which in 2 shown on the right.

A quotient formation can, for example, normalize a certain oil pressure difference Δp to a respective or the operating parameters B of a standard; this is with respect to the embodiment in 7 described in more detail.

unabhängig vom Betriebsparameter B für diesen einen Betriebsdauer-Zeitpunkt h_i.In the present case, the converter algorithm A is executed by means of a trigger at the operating time points h _i , i=1, 2, 3, the value of which is given here as Z ₁ , Z ₂ and Z _3. This means that the matrix R _i (n _MOT , T _Oil ), which comprises several oil pressure differences Δp _i for each of the time values Z ₁ , Z ₂ or Z ₃ , as they are recorded in the real operation of an internal combustion engine, is compressed for an operating time point h _i to an integrated, averaged or summed or otherwise summarized relational quantity value. ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

independent of the operating parameter B for this one operating time h _i .

und zu den Zeitpunkten hi in das Trendfeld T_a gespeichert. Anders ausgedrückt wird das 3D-Feld von links dargestellten Relationsgrößen-Werte R₁, R₂, R₃ zu frühen Betriebsdauer-Zeitpunkten h_i, i=1, 2, 3 deren Werte hier mit Z₁, Z₂ und Z₃ angegeben sind genutzt, um später Betriebswerte zu einem Wert ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

zu einem Betriebsdauer-Zeitpunkt h_i, i=1, 2, 3 zu verdichten. Dies ist in der Mitte der 5 dargestellt.The characteristic map K is therefore learned at the beginning of the engine life and then represents a reference for the standardization of all future measured values Δpi. During operation, the accumulating pressure values Δpi in the converter module W are standardized (divided) over the characteristic map K, averaged to $\overline{\mathrm{\Delta }\text{p}}$

and stored at the times hi in the trend field T _a . In other words, the 3D field of relational size values R ₁ , R ₂ , R ₃ shown on the left at early operating time times h _i , i=1, 2, 3 whose values are given here as Z ₁ , Z ₂ and Z ₃ is used to later calculate operating values to a value ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

at a time of operation h _i , i=1, 2, 3. This is in the middle of the 5 shown.

aufgetragen werden wie dies in 5 rechts dargestellt ist. Auf diese Weise entsteht ein Trendfeld über eine Anzahl von Betriebsdauer-Zeitpunkten h_i mit Werten Z₁, Z₂ und Z₃ als ${\overline{\mathrm{\Delta }\text{p}}}_1,{\overline{\mathrm{\Delta }\text{p}}}_2\text{ und }{\overline{\mathrm{\Delta }\text{p}}}_3$

usw. bis ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}.$

Es lässt sich aufgrund dieser Relationsgrößenwerte grundsätzlich eine einzige oder Schar von Trendkurven TK angeben, die sich mehr oder weniger über einen Vertrauensbereich T_B einer Trendenwicklung E verteilen. Vorliegend ist der Vertrauensbereich T_B eingefasst von einer oberen Grenzentwicklung G_o und einer unteren Grenzentwicklung G_u. Der Vertrauensbereich T_B wird vorteilhafterweise mitgeschrieben in einer Logik. Dies kann mit einer geeigneten intelligenten und gegebenenfalls lernenden Logik eines Analysemoduls 10.2 umgesetzt werden. Dabei kann beispielsweise berücksichtigt werden, dass Relationsgrößenwerte, die zuerst adaptiert wurden weniger relevant sind für einen Langzeittrend aufgrund von Einlaufeffekten an der Brennkraftmaschine. Solche und andere Randbedingungen können im Rahmen einer intelligenten Auswertung berücksichtigt werden; Beispiele dazu sind in 8 angegeben.As an output of the converter and analysis module W in the analysis module 10.2 as a result of the converter algorithm A used, sequences of operating parameter-independent relational quantity values assigned to the matrix R _i can be ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

be applied as in 5 shown on the right. In this way, a trend field is created over a number of operating time points h _i with values Z ₁ , Z ₂ and Z ₃ as ${\overline{\mathrm{\Delta }\text{p}}}_1,{\overline{\mathrm{\Delta }\text{p}}}_2\text{and}{\overline{\mathrm{\Delta }\text{p}}}_3$

etc. until ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}.$

Based on these relational values, it is basically possible to specify a single or group of trend curves TK, which are more or less distributed over a confidence interval T _B of a trend development E. In this case, the confidence interval T _B is enclosed by an upper limit development G _o and a lower limit development G _u . The confidence interval T _B is advantageously also recorded in a logic. This can be implemented with a suitable intelligent and, if necessary, learning logic of an analysis module 10.2. For example, it can be taken into account that relational values that were adapted first are less relevant for a long-term trend due to running-in effects on the internal combustion engine. These and other boundary conditions can be taken into account as part of an intelligent evaluation; examples of this can be found in 8 specified.

stellt den dazu bestimmten Öl-Differenzdruck dar.It is noticeable that in the map K the 5 for a further relational value R i added to the number of relational value values R ₁ , R ₂ , R ₃ for operating time points Z ₁ , Z ₂ , Z ₃ for an operating time point value Z _{i ,} a trend development that was previously or currently strictly monotonic is disturbed - $\overline{\mathrm{\Delta }\text{p}}$

represents the specific oil differential pressure.

in dem Trendfeld als heller Punkt eingezeichnet ist.As in the previously explained procedure within a converter module W and analysis module 10.2, a converter algorithm A triggers the Operating time points Z ₁ , Z ₂ , Z ₃ each with a matrix of relational value values R _{i ,} for example the operating time point value Z _i for a matrix of oil pressure differences Δp _i depending on engine and oil parameters n _MOT , T _Oil and forms from this an operating parameter B independent relational value value R _i , which is here referred to as ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

is shown as a bright dot in the trend field.

(hell eingezeichnet) liegt deutlich abweichend neben den dunkel eingezeichneten Betriebsparameter unabhängigen Relationsgrößen-Werten Δp1, Δp2, Δp3, die für die bisherige Trendkurve TK1 verwendet wurden - eine (lokale) Trendabweichung ΔT₁ ist also deutlich erkennbar und wird hier als sogenannte kurzfristige Trendentwicklung E₁ analysiert (wie anhand von 3 (B) erläutert). Das heißt, die Trendabweichung ΔT₁ des weiteren Relationsgrößen-Wertes ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

selbst von der zu dem Betriebszeitpunkt Z_i vorliegenden „normalen“ - kurzfristigen Trendentwicklung E₁ gemäß der bisherigen Trendkurve TK1 lässt sich etwa im Rahmen einer Differenzbildung oder sonstigen Abstandsmessung im Trendfeld T_b analysieren. Dazu können die Maßnahmen des Schritts V6 des Verfahrensablaufs in 4 vorgenommen werden. Die weiteren Schritte V7, V8 und V9 des Verfahrensablaufs in 4 lassen sich hier ebenfalls verifizieren. Es zeigt sich nämlich, dass der weitere Relationsgrößen-Wert ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

mit der Trendabweichung ΔT₁ eine Steigerung der bisherigen Trendentwicklung E₁ verringern würde; das heißt, eine weitere Trendkurve TK2 würde bei der Berücksichtigung dieses weiteren Betriebsparameterunabhängigen Relationsgrößen-Wertes ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

abnehmen - die weitere Trendkurve TK2 ist in 5 gestrichelt eingezeichnet. Dieses Ergebnis, bei dem eine streng monotone Trendentwicklung gestört ist, deutet auf eine verringerte Viskosität des Betriebsöles hin, was wiederum auf eine Öl-Verdünnung durch Kraftstoff hindeutet. Im Folgenden wird erläutert, wie eine solche Auswertung genutzt werden kann, um Einzelteil-Bestellungen für eine Brennkraftmaschine, insbesondere die Ölfilter frühzeitig zu planen.This additional operating parameter independent relational size value ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

(marked in light) is clearly different from the dark operating parameter independent relational size values Δp1, Δp2, Δp3, which were used for the previous trend curve TK1 - a (local) trend deviation ΔT ₁ is therefore clearly recognizable and is analyzed here as a so-called short-term trend development E ₁ (as shown by 3 (B) This means that the trend deviation ΔT ₁ of the further relational quantity value ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

Even the “normal” short-term trend development E ₁ according to the previous trend curve TK1 that is present at the operating time _{Z i} can be analyzed in the context of a difference formation or other distance measurement in the trend field T _b . For this purpose, the measures of step V6 of the procedure in 4 The further steps V7, V8 and V9 of the procedure in 4 can also be verified here. It turns out that the further relation size value ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

with the trend deviation ΔT ₁ would reduce an increase in the previous trend development E ₁ ; that is, a further trend curve TK2 would be calculated taking into account this further operating parameter-independent relational value ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

decrease - the further trend curve TK2 is in 5 shown in dashed lines. This result, in which a strictly monotonic trend development is disturbed, indicates a reduced viscosity of the operating oil, which in turn indicates oil dilution by fuel. The following explains how such an evaluation can be used to plan orders for individual parts for an internal combustion engine, especially the oil filters, at an early stage.

dargestellt und ein zweiter noch höherer mit „Limit Rot“ bezeichneter maximal erträglicher Relationsgrößen-Wert für einen höheren Differenzdruck $\overline{\mathrm{\Delta }\text{p}}$

dargestellt; beides als waagerechte gestrichelte Linie. 6 shows exactly the trend field T _a of the 5 with the trend development E in an enlarged representation, ie with the confidence interval T _B in a hatched representation. In addition, a first still tolerable relational value, marked “Limit Yellow”, is shown for a lower differential pressure $\overline{\mathrm{\Delta }\text{p}}$

and a second, even higher, maximum tolerable relational value, designated “Limit Red”, for a higher differential pressure $\overline{\mathrm{\Delta }\text{p}}$

both shown as horizontal dashed lines.

Of course, the trend curve on which "Case 2" is based -- namely the upper limit development G _o -- means that the "yellow limit" is reached earlier, so that the order time ET2 for an individual part in "Case 2" is significantly before the order time ET1 for an individual part in "Case 1", whereby "Case 1" is based on the lower limit development G _u and in both cases rather shorter order times of an individual part order duration are designated with t1.

However, in “Case 1”, an individual part order duration t1 (earlier expected time) is correspondingly longer until the “yellow limit” is reached than the individual part order duration t1 (earlier expected time) in “Case 2” until the “yellow limit” is reached. In both cases, however, an operational reaction is still possible; this is the result of the difference between “red limit” and “yellow limit”, since in both cases a longer individual part order duration t2 (later expected time) until the “red limit” is longer than a shorter individual part order duration t1 (earlier expected time) until the “yellow limit”. This procedure has proven to be useful, for example, when determining a filter change in order to coordinate an individual part order duration with regard to the required operational reaction. For example, a waiting time until the end of a shift in which a vehicle with the internal combustion engine is used can still be used for the “yellow limit”. However, if the “limit red” is reached, an operational reaction without delay is required. An expected time for reaching the “limit yellow” or “limit red” alarm level can be calculated using the trend curve TK explained above, which is usually located in a family of trend curves TK in the confidence interval T _B ; such a trend curve TK is shown as an example in 6 marked.

7 now also shows the possibility of such a, as in 5 to use the learned or otherwise compiled filter differential pressure map K shown in Figure 1 to detect an oil condition. In comparison to the approach of the embodiment of the 5 , shows 7 an approach that is easier to implement; for example, it is easier to program or requires less computation.

7 shows symbolically with reference to detail X of the 1 an oil filter system 1 in connection with a control and regulation scheme 11 for a control and regulation device 10. First of all, the oil filter system 1 is analogous to the representation in detail X of the 1 with an oil filter 1F for operating oil 1B in an oil line 1L for supplying oil to an engine 101 of an internal combustion engine 100. An oil differential pressure Δp is provided by means of a first and a second pressure sensor S1, S2 for determining a first and a second oil pressure p1, p2. In the present In this case, the second pressure p2 is subtracted from the first pressure p1 in a comparator 12. The comparator 12 is designed as a difference former. In principle, however, such a comparator could also establish another relationship between the second and first pressure p1, p2, for example by subtracting the first pressure from the second pressure, which would also correspond to forming a difference. However, a comparator 12 can also be designed differently, for example by forming another relationship between the second and the first pressure; for example by forming the quotient of the pressures p1, p2 - in this way, a relative pressure value can also be provided as a measure of a pressure drop across the oil filter 1F.

In the context of the present embodiment, a difference formation in the comparator 12 has proven to be advantageous, so that an oil differential pressure is made available as an actual value _{Δp_ACTUAL} within the framework of the control scheme 11.

The control and regulating device 10 is designed to execute the control and regulating scheme 11 using a characteristic map module 10.1 and an analysis module 10.2. The control and regulating scheme 11 is specifically designed with a converter algorithm A, which, as part of a quotient formation, normalizes the determined oil pressure differences Δp with a standard pressure _{Δp_NORM} to relation variable values of a trend field T _a - this is explained in more detail below.

The oil pressure relation, in the present case in the form of an oil differential pressure Δp, specifically an actual value Δp _{_ACTUAL} of the same, is related to a standard oil differential pressure Δp _{_NORM} . In the present embodiment, the standard oil differential pressure _{Δp_NORM} is the result of a standard; that is, a theoretical construct for a standard engine with certain operating parameters and the oil differential pressures associated with them via the filter 1F. The standard oil differential pressure _{Δp_NORM} is thus stored as an oil differential pressure for such a standard in a standardized oil differential pressure map K for the filter 1F.

The so-called oil differential pressure map K for standardization is in detail X of the 7 shown in more detail and stored in a first part of the map module 10.1.

The standardized oil differential pressure map K, referred to as such in the following, is similar in terms of its coordinates to the map K of the 5 formed; in contrast, however, it does not show oil differential pressure values as current measured values of the oil differential pressure measuring device 1M, but rather as standard, ie oil differential pressures to be assumed for a standard engine for operating parameter B of the engine 101.

In the present case, in the standardized oil differential pressure map K, these are again the oil temperature T _oil and the engine speed n _MOT for which standard oil differential pressures are recorded as standard pressures Δp_ _NORM . This essentially corresponds to a matrix in which a standard oil differential pressure Δp _NORM is recorded as a standard in relation to an oil temperature T _oil and an engine speed n _MOT . In this respect, the oil differential pressure map K for the filter 1F is referred to here as K _NORM . The standardized map K _NORM is stored in the map module 10.1 and is connected for control purposes to the output of the comparator 12, which supplies the actually measured oil differential pressure Δp, namely its actual value Δp _{_IST} . Furthermore, the map module 10.1 has inputs not only for parameters of the engine speed n _MOT and the oil temperature T _Oil , but other operating parameters B can also be included. As an example of further operating parameters B, performance parameters (for example torque or a torque requirement or a coolant temperature T _KM) are listed here for the standardization oil differential pressure map K _NORM .

The standardization oil differential pressure map K _NORM is a multidimensional map with five coordinates in which the normal oil differential pressure is set in relation to a standard engine, i.e. it is set in relation to a number of operating parameters B; in this case, mainly speed n _MOT and operating oil temperature T _Oil as well as torque or a torque requirement or a coolant temperature T _KM are shown in more detail.

The converter algorithm A provides that the measured differential pressure Δp (specifically its actual value Δp _IST ) is standardized in relation to the standardization oil differential pressure map K _NORM as part of a quotient formation - the corresponding converter algorithm provides for a quotient generator 13 which standardizes the oil differential pressure Δp --as measured-- in relation to the standard oil differential pressure Δp _NORM in an acute operating situation of the engine (determined by the aforementioned operating parameters B: n _MOT TKM T _Oil load point M).

This can be done, for example, in such a way that for a specific known operating parameter B such as engine speed n _MOT and operating oil temperature T _Oil, the standard oil differential pressure Δp _NORM is taken from the standard map K _NORM as a known standard value and the actually measured oil differential pressure Δp in the quotient former 13 of a division is fed to form a standardized relational value R in the sense of $$\text{R}=\frac{\mathrm{\Delta }\text{pIST}}{\mathrm{\Delta }\text{pNORM}\left(\left(\text{nMOT},\text{T}\ddot{\text{O}}\text{l}\right)\right)}.$$

According to the present embodiment, the relational quantity value R to be used in the control and regulation scheme 11 is a standardized relational quantity value R which is recorded in a standardized trend field for a plurality of operating time points h _i for a specific operating time.

In the present example of the control scheme 11, this is shown in more detail Y as part of the characteristic map module 10.1 in a trend field T _a - that is, to record the standardized oil differential pressure -- the oil differential pressure Δp is standardized with a standard oil differential pressure Δp _NORM -- a number of standardized relational quantity values R _i for operating time points h _i are repeatedly plotted within the framework of the control scheme executed with difference former 12 and quotient former 13.

1. 2. Öl-Verdünnung.
2. 3. Filtertausch
3. 4. Öl-Nachfüllvorgang

This separation field is made available as a standardized separation field T _a to a previously mentioned analysis module 10.2 for carrying out a trend analysis as described by 2 , 5 and 6 has already been explained. In the standardized differential pressure map T _a, a value R _j of a standardized relational quantity value with an open symbol is also shown, which indicates a trend deviation. This means that the further relational quantity value R _j causes a trend deviation ΔT from the trend development E to below the trend development E. The determination of this trend deviation ΔT can be carried out using a specific mathematical procedure in the analysis module 10.2. The concept of the invention has -- as previously explained -- also recognized that oil quality is of crucial importance for the service life of an engine, whereby in the analysis module 10.2, four superimposed effects are recognized in particular, namely recognized and differentiated as a result of the speed of their individual trend. 1. Oil aging and

1. 2. Oil dilution.
2. 3. Filter replacement
3. 4. Oil refilling process

The first two effects lead to a reduction in viscosity; the difference lies primarily in the strength of the trend. While a viscosity change due to normal engine operation is observable over hundreds of hours, the viscosity change due to oil dilution occurs within a few hours. This is used to detect/distinguish due to the speed of their individual trend.

Additionally, the effect of the filter is superimposed - as the filter load increases, the differential pressure across the filter increases, which corresponds to a slow trend.

When changing a filter, a change in the oil differential pressure occurs suddenly as a drop in pressure. A change in the oil differential pressure in the form of a sudden increase occurs when oil is refilled and also occurs suddenly.

mit den zuvor genannten normierten Relationsgrößen-Werten R_i einer Trendentwicklung E über die Betriebsdauer h_B einer Brennkraftmaschine mit einem Motor 101 und dem Ölfiltersystem 1. Die Darstellung der normierten Öl-Differenzdrücke $\overline{\mathrm{\Delta }\text{p}}$

ist zu verstehen mit der Trendentwicklung E auf einer Skala von Betriebsdauern im Bereich von mehreren zehntausend Stunden, also beispielsweise im Bereich einer Betriebsdauer h_B von etwa 20.000 Stunden. 8A shows an example of a concrete course of the standardized oil differential pressure $\overline{\mathrm{\Delta }\text{p}}$

with the previously mentioned standardized relational quantity values R _i of a trend development E over the operating time h _B of an internal combustion engine with an engine 101 and the oil filter system 1. The representation of the standardized oil differential pressures $\overline{\mathrm{\Delta }\text{p}}$

is to be understood as the trend development E on a scale of operating times in the range of several tens of thousands of hours, for example in the range of an operating time h _B of about 20,000 hours.

in Folge eines sich zunehmend zusetzenden Filters 1F ansteigt. Eine nach unterhalb einer ansteigenden Normal-Trendentwicklung abnehmende Trendentwicklung ist somit als die relevante Trendabweichung ΔT zu analysieren.Shown in 8A a selection of trend deviations ΔT _i at specific operating time points h _i , which are designated here with R _j (i=0,1,2,3) and can be assigned to different events B _i (i=0,1,2,3). A running-in period of the engine with the operating time h _B =0 (e.g. specified in operating hours) is not taken into account; so to speak, the value R ₀ of an operating time h _B has an offset O at the event B ₀ . A trend development E in the form of a normal trend development will be recognizable as increasing over the operating time h _B , in particular monotonically increasing in a diesel engine, since the oil differential pressure $\overline{\mathrm{\Delta }\text{p}}$

as a result of an increasingly clogged filter 1F. A trend development that decreases below an increasing normal trend development is therefore to be analyzed as the relevant trend deviation ΔT.

The events B _i (i=1, 2, 3, 4) shown here are different examples with corresponding deviating standardized relational quantity values R _j 1, R _j 2, R _j 3, R _j ''' from the trend development with correspondingly caused trend deviations ΔT1, ΔT2 and ΔT3, or ΔT3'.

During oil ageing of event B4, the viscosity should essentially decrease over time, as the long-chain hydrocarbon chains are broken down by mechanical shear forces. Oil ageing causes a decreasing Trend signature of oil ageing in the trend, which is superimposed on the increasing normal trend development - this is recognizable on the long scale of an operating time point h4 in sub-linear deviation from the linearly increasing trend E. In the context of oil dilution, the viscosity should also decrease, but due to other processes on a different time scale.

If the oil is diluted (ÖV1, ÖV2) in event B3, there is also a downward trend of differential pressure loss. In other words: within the filter model, the trend of an increasing relational variable that takes the first and second oil pressures into account weakens as a result of oil dilution. A trend deviation between the other relational variable value and the trend development can then be evaluated in different ways; for example, it can be advantageously analyzed within the framework of the short-term or long-term trend development above. Event B1 at operating time h1 indicates a filter change and event B2 at operating time h2 indicates an oil refill process.

zur Folge; mit Vorteil versehen also auf sehr kurzer Zeitskala (praktisch instantan) erkennbar im Vergleich zu einer an sich bereits kürzeren Zeitskala der Öl-Verdünnung.The filter replacement at event B1 at operating time h1 has a suddenly decreasing trend deviation due to the suddenly decreasing oil differential pressure $\overline{\mathrm{\Delta }\text{p}}$

as a result; advantageously, it can be detected on a very short time scale (practically instantaneously) compared to an already shorter time scale of oil dilution.

A change in oil differential pressure in the form of a sudden increase results from the refilling of oil and also occurs suddenly in event B2.

Thus, further relational quantity values R _i+1 can be analyzed in relation to a decreasing trend deviation ΔT from the trend development E caused by at least one further relational quantity value R _i+1 as the relevant trend deviation ΔT, wherein the time extension and/or amplitude, in particular ramp, of the decreasing trend deviation ΔT from the trend development E is analyzed.

The event B3 at operating time h3 to operating time h4 comprises two variants of an oil dilution process ÖV1, ÖV2.

The events B1, B2 represent recognizable events such as the filter change (B1) and the oil refill process (B2).

The rapid process of oil dilution ÖV1 of event B3 is the presently relevant alarming process which is detected within the framework of the preferred embodiment within the framework of the concept for inventing a trend analysis by means of the oil differential pressure measuring device 1M and the control scheme 11 using the control and regulating device 10. The individual events are explained below.

8B shows in view (A) a previously explained model of a long-term trend development E _g (as shown in 3 View (A) explains) and a variant of an analysis. A global trend deviation ΔT _g can be coordinated with the further relational quantity value R _i as trend development E _g . The previous trend curve TK1 can also be referred to as the normal trend development and the further trend curve TK2 can be referred to as the deviated trend development in comparison to the normal trend development.

The trend curve TK1 of the normal trend development is created based on the previously mentioned values ${\overline{\mathrm{\Delta }\text{p}}}_1,{\overline{\mathrm{\Delta }\text{p}}}_2\text{and}{\overline{\mathrm{\Delta }\text{p}}}_3.$

für den Betriebsdauer-Zeitpunkt Z_i aufgetragen. Die Trendkurve TK2 der abgewichenen Trendentwicklung entsteht unter Berücksichtigung des Weiteren Relationsgrößen-Wertes R_i.In addition, an operating parameter is an independent relational value ${\overline{\mathrm{\Delta }\text{p}}}_{\text{i}}$

for the operating time Z _i . The trend curve TK2 of the deviated trend development is created taking into account the additional relational quantity value R _i .

1. 1. Zu geringer Öldruck: Defekt im Motor / fehlendes Öl => Notabstellung
2. 2. Zu hoher normierter Differenzdruck => Filtertausch erforderlich => Wartungslampe
3. 3. Ereignis B4: Langsam steigernder Differenzdruck => Wartungsprognose für Filtertausch
4. 4. Schneller Anstieg des Differenzdruckes => Vermutlich innere abrasive Abnutzung (Späne) Motordefekt => Warnung
5. 5. Ereignis B3: Schnelle (innerhalb weniger Stunden, nicht plötzliche) Absenkung ÖV1 des normierten Δp nach unten => Öl-Verdünnung => Alarm gemäß dem Konzept der Erfindung. Es kann beispielsweise festzustellen sein, ob Dieselkraftstoff in den Ölkreislauf gelangt. Dies führt nämlich zu einem maßgeblichen Verlust der Schmierfähigkeit, sodass verschiedene Defekte, wie zum Beispiel Lager- oder O-Ring-Defekte in der Kraftstoffpumpe durch diesen Verlust der Schmierfähigkeit hervorgerufen werden können.
6. 6. Ereignis B1: Plötzliche Absenkung des normierten Δp nach unten => Ursache: Filtertausch => (auch für Big Data Analyse - Alarmunterdrückung vom Öl-Verdünnungsalarm)
7. 7. Der Wert des Δp nach Filtertausch ist ein Maß für die Ölqualität => Wartungshinweis Filtertausch ohne Ölwechsel (nicht Gegenstand der Erfindung)
8. 8. Ereignis B2: Plötzlicher Anstieg des normierten Δp nach oben => Öl wurde nachgefüllt. (auch für Big Data Analyse bzw. in Abgrenzung zu 4.)
9. 9. Ereignis B0: Ausblenden der ersten 100 Motorbetriebsstunden zur Verhinderung einer Fehlanzeige der Trendentwicklung.

A method of oil condition detection can particularly preferably comprise the following test steps:

1. 1. Too low oil pressure: Defect in the engine / missing oil => emergency shutdown
2. 2. Standard differential pressure too high => filter replacement required => maintenance lamp
3. 3. Event B4: Slowly increasing differential pressure => maintenance forecast for filter replacement
4. 4. Rapid increase in differential pressure => Probably internal abrasive wear (chips) Motor defect => Warning
5. 5. Event B3: Rapid (within a few hours, not sudden) reduction in ÖV1 of the standardized Δp => oil dilution => alarm according to the concept of the invention. For example, it can be determined whether diesel fuel is entering the oil circuit. This leads to a significant loss of lubricity, so that various defects, such as bearing or O-ring defects in the fuel pump, can be caused by this loss of lubricity.
6. 6. Event B1: Sudden reduction of the normalized Δp downwards => Cause: filter replacement => (also for Big Data Analysis - alarm suppression of oil dilution alarm)
7. 7. The value of Δp after filter replacement is a measure of the oil quality => Maintenance note Filter replacement without oil change (not subject of the invention)
8. 8. Event B2: Sudden increase of the normalized Δp upwards => oil was refilled. (also for big data analysis or in contrast to 4.)
9. 9. Event B0: Hiding the first 100 engine operating hours to prevent incorrect display of the trend development.

8B shows in view (A) a preferred consideration of a first boundary condition for both trend curves TK1 and TK2; namely such that a running-in time of the engine is not taken into account in the operating time h _B (e.g. specified in operating hours); so to speak, the value Z of an operating time h _B has an offset O.

The running-in period of the engine ultimately causes data that cannot be evaluated due to the strong fluctuation amplitudes in the viscosity of the operating oil and the offset O that takes this into account is in the 8A shown hatched.

selbst von der zu dem Betriebszeitpunkt vorliegenden normalen Trendentwicklung (dunkle Punkte) analysiert. 8B shows in view (B) the case of a short-term trend development E ₁ (as shown in 3 View (B) explains a variant of the trend development T _b to determine a local trend deviation ΔT ₁ . In the event that further relational size values Δp _i fall significantly and relatively quickly (ÖV1) below the previous trend development T _b (dark points), this can be analyzed as a short-term trend development E _1. For this purpose, a local trend deviation ΔT _e of the further relational size value $\overline{\mathrm{\Delta }\text{p}}$

even from the normal trend development present at the time of operation (dark points).

--nämlich betreffend die in 1 dargestellte Öldruck-Differenz zwischen dem zweiten Öldruck und dem ersten Öldruck, Δp = p2 - p1 über den Filter-- stark negativ ist; das heißt ein Wert $\overline{\mathrm{\Delta }\text{p}}$

sinkt abrupt zu einem Zeitpunkt Z, was in 8C symbolisch durch „X“ dargestellt ist. 8B shows in view (C) a further boundary condition such that a filter exchange takes place at time Z on a scale of operating time h _B ; this event is followed by a new indication of the trend development. This means that the trend memory is first deleted at time Z, which in 8C symbolically represented by “X”. The background is that when a filter is replaced, the temporal change Δp/Δt of the operating parameter independent relational quantity value symbolically represented by a downward arrow $\overline{\mathrm{\Delta }\text{p}}$

--namely concerning the 1 shown oil pressure difference between the second oil pressure and the first oil pressure, Δp = p2 - p1 across the filter-- is strongly negative; that is, a value $\overline{\mathrm{\Delta }\text{p}}$

drops abruptly at a time Z, which results in 8C symbolically represented by “X”.

In this case, the trend analysis would have to start again from the beginning and all "L1p" values would have to be set back to "0". After that, increasing differential pressure values relating to the oil pressure difference between the second oil pressure and the first oil pressure, Δp = p2 - p1, would be recorded via the filter in the map. These are then converted using the described converter and analysis module W or the corresponding converter algorithm A and then entered in the trend field T _c for further trend analysis using one of the methods described above.

REFERENCE SYMBOL LIST

1

oil filter system

1B

operating oil

1F

oil filter

1M

oil differential pressure measuring device

10

control and regulation device

10.1

map module

10.2

analysis module

1L

oil pipeline

100

internal combustion engine

101

Motor

102

air duct systems

103

Heat exchanger

104

oil supply system

ECU

engine control unit

A

converter algorithm

W

converter module

B

operating parameters

K, KNORM

map, standard map

D

sensor data

X

detail

SW

threshold

R, R1, R2, R3 ...Ri, Ri+1

relation size, relation size values, further relation size value

S

sensor system

S1

first pressure sensor

S2

second pressure sensor

p1

first oil pressure

p2

second oil pressure

E, Eg, E1

trend development, long-term trend development, short-term trend development

T, Ta, Tb, Tc

Trend field, first, second, third trend field with developing trend curve to determine a trend deviation ΔT

TK, TK1, TK2

trend curve, previous and further trend curve

TÖl

oil temperature

TB

confidence interval

oil

oil parameters

MOTS

engine parameters

hB

operating time

hi

operating time

M

load point

MMOT

engine torque

nMOT

engine speed

BP

operating parameters

Mean value of the oil pressure difference Δp _i for the relational quantity R

Δ, ΔT

Deviation Trend Deviation

ΔTg

global trend deviation

ΔT1

local trend deviation

Δpi

oil pressure difference

Go

upper limit development

Gu

lower limit development

Z, Z1, Z2, Z3, Zi

Value of an operating time point h _i , i=1, 2, 3, at which the relational quantity values R _i are determined

t1

early expected date, individual part order duration up to the "yellow limit"

t2

later expected time, individual part order duration up to the "red limit"

ET1

Order time for a single part in "Case 1"

ET2

Order time for a single part in "Case 2"

O

offset for run-in time

Claims (25)

Method for detecting an oil condition of an operating oil in an engine (101) of an internal combustion engine (100), in particular for a diesel, Otto or gas engine, wherein the internal combustion engine has the engine (101) and: - an oil supply system (104) with an oil filter (1F) for the operating oil (1 _B ) and an oil differential pressure measuring device (1M) designed to detect an oil pressure difference (Δpi) or similar oil pressure relation of the operating oil via the oil filter (1F) in the oil supply system (104), - a control and/or regulating device (10) with a characteristic map module (10.1) and an analysis module (10.2) for the oil pressure difference (Δp _i ), wherein in the method: - the oil pressure difference (Δp _i ) is processed in relation to an operating time (hB) of the internal combustion engine in the analysis module (10.2), - a number of Oil pressure difference (Δp _i ) is taken into account in relation to a number of operating time points (hi), - the number of relational value values (R1, R2, R3, Ri) is assigned to a trend development (E) over the operating time points (hi), characterized in that - the oil pressure difference or similar oil pressure relation is recorded in a characteristic map (K) in relation to a number of operating parameters (B) of the engine and/or oil parameters of the operating oil, and - the oil pressure difference (Δp _i ) or similar oil pressure relation determined via the oil filter (1F) is assigned to a value independent of the operating parameters (B). - for a further operating time point (hi) added to the number of operating time points (hi), a further relational quantity value (R _i+1 ) is analyzed in relation to a relevant trend deviation (ΔT) from the trend development (E) caused by at least one further relational quantity value (R _i+1 ), namely by means of a changed trend development. procedure according to Claim 1 , characterized in that the relevant trend deviation (ΔT) results as a decrease in the trend development by means of the changed trend development, in particular as a decreasing trend deviation. procedure according to Claim 1 or 2 , characterized in that - the trend development (E) is increasing in the form of a first variant of a normal trend development over an operating period (h _B ), wherein the relevant trend deviation (ΔT) is recognizable as a decrease in the trend development by means of the changed trend development, preferably in the case of a diesel or gasoline engine. procedure according to Claim 1 or 2 , characterized in that - the trend development (E) in the form of a second variant of a normal trend development is constant or decreasing over an operating period (h _B ), wherein the relevant trend deviation (ΔT) can be recognized as an increase in the trend development by means of the changed trend development, preferably in the gas engine. Method according to one of the Claims 1 until 4 , characterized in that the further relational size value (R _i+1 ) is below the current trend development (E), in particular below a previous trend curve (TK), whereby - the slope of a relevant trend development (E) decreases with the further relational size value (R _i+1 ) in comparison to the current trend development (E), in particular in comparison to the previous trend curve (TK). Method according to one of the Claims 1 until 4 , characterized in that the further relational size value (R _i+1 ) is below a normal trend development, wherein the slope of a relevant trend development (E) decreases with the further relational size value (R _i+1 ) in comparison to a normal trend development. procedure according to claim 5 or 6 , characterized in that a positive gradient value of the trend development decreases or becomes negative or a negative gradient value continues to decrease. Method according to one of the Claims 1 until 7 , characterized in that the further relational quantity value (R _i+1 ), in relation to a relevant trend deviation (ΔT) from the trend development (E) caused by at least one further relational quantity value (R _i+1 ), is analyzed over time by means of the changed trend development in order to determine a speed of the relevant trend deviation (ΔT). Method according to one of the Claims 1 until 8 , characterized in that - the time extension and/or amplitude, in particular ramp, of the relevant trend deviation (ΔT) from the trend development (E) is analyzed in the changed trend development. procedure according to claim 9 , characterized in that - a trend development of a decreasing trend deviation (ΔT) is recognized as a relevant trend development (E), for which the time extension has a finite value above 5 minutes and up to ten hours. Method according to one of the Claims 5 until 10 , characterized in that a relevant trend development (E) of the relational variable is stored in a filter model by processing the oil pressure relation of a first and second oil pressure (p1, p2) by means of a relational variable (R) taking this into account in relation to an operating time (hB) of the internal combustion engine, wherein the relevant trend development (E) of the relational variable is discriminated against by means of the filter model. procedure according to claim 11 , characterized in that - the relevant trend development (E) of the relational quantity is discriminated by means of the filter model for distinguishing a relevant effect of oil aging and oil dilution as a comparatively rapid but not sudden trend development of a relevant trend development (E) from other effects, whereby a decreasing trend development of oil aging and/or oil dilution in the trend is superimposed by an increasing normal trend development, and/or - the relevant trend development (E) of the relational quantity is discriminated by means of the filter model relating to one or more trend developments for a running-in period of the engine, a filter change and/or an oil refill, whereby - for the running-in period of the engine, a trend development of a running-in period in the trend is not taken into account in the operating time, - the filter change is a suddenly decreasing or increasing trend development in the trend is followed by a new indication of the trend development, - the oil refill is a trend development of the oil refill suddenly increasing or moderately increasing. Method according to one of the Claims 1 until 12 , characterized in that the oil differential pressure measuring device (1M) has a first pressure sensor (S1) arranged in the flow direction upstream of the oil filter (1F) and a second pressure sensor (S2) arranged in the flow direction downstream of the oil filter (1F), optionally has an override valve for regulating a maximum oil pressure, and the method, in particular taking into account the regulation of a maximum oil pressure, has the further step: - detecting and indicating a first oil pressure (p1) upstream of the oil filter (1F) by means of the first pressure sensor and a second oil pressure (p2) downstream of the oil filter (1F) by means of the second pressure sensor, wherein - the first and second oil pressures (p1, p2) are processed as the oil pressure difference (Δp _i ) by means of an oil pressure relation of the operating oil via the oil filter (1F) in the oil guide system (104) which takes these into account. Method according to one of the Claims 1 until 13 , characterized in that - a standard characteristic map (K _NORM ) of standard differential pressures is created for a standard engine and/or a standard operating oil in relation to a number of operating parameters (B) of the engine and/or oil parameters of the operating oil, and/or - the oil pressure difference or similar oil pressure relation is converted to a standardized oil pressure difference or similar standardized oil pressure relation, in particular by means of the standard characteristic map (K _NORM ) of standard differential pressures in relation to the number of operating parameters (B) of the engine and/or oil parameters of the operating oil. procedure according to claim 13 or 14 , characterized in that - for each relational quantity value (R1, R2, R3, Ri) at an operating time (hi) a number of oil pressure relations of the second and first oil pressure (p2, p1) are formed, in particular the oil pressure difference (Δp _i ) of the second and first oil pressure (p2, p1) is formed, and/or - for an oil pressure difference (Δp _i ) or similar oil pressure relation, a standardized relational quantity value is formed and/or for the second and first oil pressure (p2, p1) a standardized second and first oil pressure (p2, p1) is formed, in particular by means of a standard characteristic map (K _NORM ). procedure according to claim 14 or 15 , characterized in that - for an operating time (hi) the standardized relational variable value is formed as a quotient of the oil pressure difference or similar oil pressure relation and an associated variable of the characteristic map (K) and/or the standard characteristic map (K _NORM ) for an operating parameter (B) of the engine and/or oil parameter. Method according to one of the Claims 14 until 16 , characterized in that a standardized relational variable value for an oil pressure difference is formed by means of a converter algorithm (A) assigned to the engine to the standardized relational variable value for the operating time (hi), in particular wherein the converter algorithm (A) has a quotient, averaging and/or integration by means of a standard characteristic map (K _NORM ) of standard differential pressures in relation to the number of operating parameters (B) of the engine and/or oil parameters of the operating oil. Method according to one of the Claims 1 until 17 , characterized in that the number of operating parameters (B) comprise at least operating parameters of the engine and/or oil parameters of the operating oil, namely at least one engine speed (n _MOT ) and one operating oil temperature (T _Oil ), optionally also comprise performance parameters from the group torque, torque requirement and coolant temperature (T _KM ). Method according to one of the preceding claims, characterized in that - the trend deviation (ΔT) is evaluated by means of a deviation determination, in particular by means of a difference formation, and/or - it is recognized that the trend deviation is significant, wherein a condition signal is output which indicates a significantly impaired oil condition. Method according to one of the preceding claims, characterized in that a short-term trend development (E ₁ ) is analyzed in such a way that a temporally local trend deviation (ΔT ₁ ) of the further relational quantity value (R _i+1 ) itself is analyzed in relation to the normal trend development present at the time of operation, in particular the previous trend curve (TK1). Method according to one of the preceding claims, characterized in that a long-term trend development (E _g ) is analyzed in such a way that a temporal global trend deviation (ΔT _g ) of a trend development determined with the further relational quantity value (R _i+1 ), in particular a further trend curve (TK2), is analyzed in relation to the previous trend curve (TK1) present at the time of operation. Method according to one of the preceding claims, characterized in that for a normal trend development - an upper limit development (G _o ) and a lower limit development (G _u ) are specified, and/or - an earlier and a later expected time (t1, t2) for a state signal are specified. Control and/or regulating device (10), in particular for controlling and/or regulating an internal combustion engine (100), for detecting an oil condition of an operating oil (1B) for an engine (101) of the internal combustion engine, in particular for a diesel, petrol or gas engine, wherein the control and regulating device has a characteristic map module (10.1) and an analysis module (10.2) for an oil pressure difference and is designed to carry out a method according to one of the Claims 1 until 22 to be carried out, wherein the control and regulating device (10) comprises: - the analysis module (10.2) for the oil pressure difference (Δp _i ) or similar oil pressure relation taking into account relational quantity values (R1, R2, R3, Ri) in relation to a number of operating time points (hi), which is designed to process the oil pressure difference (Δp _i ) in relation to an operating time (h _B ) of the internal combustion engine and has: - an operation recorder and converter (W), in which a number of relational quantity values (R1, R2, R3, Ri) taking into account the oil pressure difference (Δp _i ) in relation to a number of operating time points, - a trend generator, by means of which a trend development (E) is assigned to the number of relational quantity values (R1, R2, R3, Ri), characterized by - the characteristic map module (10.1), wherein the oil pressure difference or similar Oil pressure relation in relation to a number of operating parameters (B) of the engine and/or oil parameters of the operating oil is recorded in a characteristic map (K), whereby - the oil pressure difference (Δp _i ) or similar oil pressure relation determined via the oil filter (1F) is converted to a relational quantity value (R1, R2, R3, Ri) independent of the operating parameters (B) and is indicated in relation to the number of operating time points (hi), and - a deviation generator, by means of which a further relational quantity value (R _i+1 ) for a further operating time point (hi) added to the number is analyzed in relation to a trend deviation (ΔT) from the trend development (E) caused by at least one further relational quantity value (R _i+1 ), namely by means of a changed trend development. Internal combustion engine (100) with an engine, in particular a diesel, Otto or gas engine, and with an oil supply system (104) comprising an oil filter (1F) for the operating oil and an oil differential pressure measuring device (1M) which is designed to detect and indicate an oil pressure difference (Δp _i ) or similar oil pressure relation of the operating oil via the oil filter (1F) in the oil supply system (104), wherein - the internal combustion engine has a control and/or regulating device according to claim 23 has. internal combustion engine (100) after claim 24 , characterized in that the control and/or regulating device is designed to control and regulate the internal combustion engine.

Images